UC-NRLF 


GURLEY'S    MANUAL 


AMERIf /VN 
ENCI N EEIS'AND  SURVEYORS' 


^  L-.:- «:,-••  •;:.•••  ':  •.  r;  CM^ 


LIBRARY 


UNIVERSITY  OF  CALIFORNIA. 


Gl  FT    OF 


In 


m 


A    MANUAL 


OF    THE   PRINCIPAL 


INSTRUMENTS 


AMERICAN   ENGINEERING 
AND    SURVEYING 


MANUFACTURED    BY 


W.   &   L.    E.    GURLEY 

TROY,  N.  Y.,  U.  S.  A. 


FORTY-SECOND    EDITION 


TROY,  N  .  Y  . 
PUBLISHED  BY  W.  &  L.  E.  GURLEY 

AUGUST,  1908 


PRICE    50   CENTS 


— 

d*  according  to  Act 


Entered*  according  to  Act  of  Congress,  in  the  Year  1908 

•BY  W.  &  L.  E.  GURLEY 
[n  the  Office  of  the  Librarian  of  Congress,  at  Washington 


MATTHEWS-NORTHRUP 


""3 
*    '•<•• 

v 


UN1VER 

OF       -    -  / 


ESTABLISHED  1845  INCORPORATED  1900 

1845-1908 


PREFACE  TO  THE  FORTY-SECOND  EDITION 


TV/TORE  THAN  SIXTY  YEARS  AGO  the  manufacture 
•*•*•*•  of  Civil  Engineers'  and  Surveyors'  instruments  in  this 
city  was  begun  by  Jonas  H.  Phelps  and  William  Gurley. 
Mr.  Phelps  retiring  some  years  later,  William  Gurley  formed 
with  his  brother,  Lewis  E.  Gurley,  the  firm  of  W.  &  L.  E. 
Gurley,  and  under  this  name  the  business  has  since  been 
conducted. 

The  first  edition  of  GURLEY' s  MANUAL,  a  book  of  seventy 
pages,  was  published  in  1855,  and  was  the  first  really  practi- 
cal treatise  on  the  use  and  adjustment  of  Civil  Engineers' 
and  Surveyors'  instruments.  The  revised  and  enlarged 
MANUAL  is  used  as  a  text -book  in  many  schools  and  colleges, 
and  is  freely  quoted  in  technical  publications. 

The  capacity  of  our  factory  has  been  increased  as  the 
demand  for  such  instruments  has  grown,  until  we  are  the 
most  extensive  manufacturers  of  Civil  Engineers'  and  Sur- 
veyors' instruments  in  the  world.  We  have  recently  added 
two  departments  to  our  factory,  and  now  manufacture  ther- 
mometers of  high  grade,  and  also  physical  and  scientific 
apparatus  of  all  kinds. 

We  are  glad  to  have  all  our  manufactures  judged  upon 
their  merits,  and  invite  the  most  critical  examination. 

W.   &    L.   E.   GURLEY, 

TROY,  N.  Y.,  U.  S.  A. 
4 


TRANSIT-  INSTRUMENT 


*T«HE  AMERICAN  TRANSIT  is  by  far  the  most  impor- 
•"-  tant  instrument  used  in  engineering.  The  essential 
parts,  which  may  be  seen  in  the  cuts,  are  the  telescope  with 
its  axis,  the  standards,  the  circular  plates  with  their  attach- 
ments, the  sockets  upon  which  the  plates  revolve,  the 
leveling-head,  and  the  tripod  upon  which  the  whole  instru- 
ment stands. 

The  telescope  is  secured  in  an  axis  having  its  bearings 
fitted  in  the  standards,  allowing  the  telescope 
to  transit.      The  different  parts  of   the  tele- 
scope are  shown  in  the  cut  on  page  7. 

The  objective  is  an  achromatic  lens  placed  at  the  end 

of  a  slide  having  two  bearings,  one  at  the  end  of  the  outer 

tube,  the   other   in   the   ring,  C   C,   which    is 

OBJECTIVE  j    j        •  u-  r 

suspended  witinn  the  tube  by  four  screws,  only 
two  of  which  are  shown  in  the  cut. 

The  eyepiece  is  composed  of  four  lenses  which  are  called 

respectively  the  eye,  the  field,  the  amplifying,  and  the  object 

lens,   the    whole    formimg    a    compound    micro- 

EYEPIECE  . 

scope  focusing  on    the   cross-wires   attached   to 
the  ring,  B  B. 

In  all  our  transits,  with  the  exception  -of  the  Explorers', 
Reconnoissance,  and  Builders'  Transits,  both  the  objective 
and  eyepiece  are  moved  out  or  in  by  pinions  working  in 
racks  attached  to  their  sides,  and  are  thus  adjusted  to  proper 
focus.  In  the  instruments  named,  the  eyepiece  is  focused  by 
a  spiral  movement. 

5 


|72837 


TRANSIT-INSTRUMENTS 


NO.    12 

Engineers'  Transit,  two  verniers  to  limb,  with  5  inch  needle,  plain  telescope,  and  tripod. 
Price,  as  shown,  $150.00. 


TRANSIT-INSTR  UMENTS 


Sometimes  an  eyepiece  with  but 
two  lenses  is  used,  but  while  this  gives 
INVERTING  more  light  it  presents  an 
EYEPIECE  inverted  image  of  the 
object  observed,  and  it  is  not  often 
desired  by  American  engineers. 

The  objective,  receiving  the  rays  of 

light  from  all  points  of  a  visible  object, 

V.S.ON  A.DED      Converges   them   to    a 

BY  focus     at     the     cross- 

TELESCOPE          wires?  and  there  forms 

a  minute,  inverted  image,  which  may 
be  seen  by  placing  a  piece  of  ground 
glass  at  that  point  to  receive  it. 

The  eyepiece  magnifies  this  image, 
restores  it  to  its  natural  position  and 
conveys  it  to  the  eye. 

The  visual  angle  which  the  image 
subtends  is  as  many  times  greater  than 
MAGNIFYING      tnat    which    would     be 
POWER  formed  without  the  aid 

of  the  telescope  as  the  number  which 
expresses  its  magnifying  power  is  greater  B 
than  unity.  Thus,  a  telescope  which 
magnifies  twenty  times  increases  the 
visual  angle  in  the  same  proportion, 
and  therefore  diminishes  the  apparent 
distance  of  the  object  twenty  times. 
In  other  words,  it  will  show  an  object 
two  hundred  feet  distant  with  the  same 
distinctness  as  if  it  were  only  ten  feet 
distant  from  the  naked  eye. 


8 


TRA  NSIT-  INS  TR  UMENTS 


HIGH    POWERS 


It  is  often  supposed  that  the  greater  the  power  of  a  tele- 
scope the  better;  but,  beyond  a  certain  limit,  this  is  not 
true.  As  only  a  given  amount  of  light  can 
enter  the  objective,  the  more  the  object  is 
magnified  the  less  clear  and  bright  will  it  appear.  We  have 
found  that  a  power  of  from  twenty  to  twenty-four  diameters 
in  the  telescopes  of  transits  gives  the  best  results,  and  is  suf- 
ficient for  all  ordinary  practice. 

The  cross -wires  are  two  wires 

of   very  fine   platinum,  mounted 

•   on    the    face    of 

CROSS-WIRES 

a   metal    ring 

They  are  placed  at  right  angles' 
with  each  other,  so  as  to  divide 
the  space  in  the  center  into 
quadrants. 

The  advantage  of  platinum 
over  spider-web  for  the  cross-wires  of  telescopes  has  long 
PLATINUM  been  conceded,  but  the  difficulty  of  pro- 
c ROSS- WIRES  curing  it  of  sufficient  fineness  has  prevented 
its  general  use.  We  are  successfully  drawing  platinum  wires 
of  from  one  eight -thousandth  to  one  fifty-thousandth  of  an 
inch  in  diameter,  and  are  using  them  in  the  telescopes  of  all 
our  instruments.  These  wires  are  opaque  and  unaffected  by 
moisture,  and  are  universally  preferred  to  the  spider-web 
formerly  used. 

The  intersection  of  the  wires  forms  a  point  which,  when 

adjusted,  enables  the  surveyor  to  fix  the  telescope  upon  an 

object    with    the    greatest    precision.       The 

OPTICAL  AXIS        .  ..  fe  . 

imaginary  line  passing  through  the  optical 
axis  of  the  telescope  is  called  the  line  of  collimation,  and 
the  process  of  bringing  the  intersection  of  the  wires  into  the 


TRANSIT-INSTRUMENTS  9 

optical  axis  is  called  the  adjustment  of  the  line  of  colli- 
mation.     This  is  described  on  pages  22  to  24. 

The  sectional  view  of  the  telescope  on  page  7  shows  two 
movable  rings,  one  at  A  A,  the  other  at  C  C,  which  are  used 
respectively  in  centering  the  eyepiece  and  in  the  adjustment 
of  the  objective  slide. 

The  centering  of  the  eyepiece  is  effected  after  the  wires 
have  been  adjusted,  by  moving  the  ring,  by  means  of  the 
screws  shown  on  the  outside  of  the  tube,  until  the  intersection 
of  the  wires  is  brought  into  the  center  of  the  field  of  view. 

The  adjustment  of  the  objective  slide,  which  is  described 
on  page  25,  keeps  the  line  of  collimation  in  adjustment 
through  the  whole  range  of  the  slide.  This  is  peculiar  to 
our  telescopes,  is  always  made  in  the  process  of  manufacture, 
and  needs  no  attention  from  the  engineer,  unless  the  instru- 
ment is  severely  injured. 

The  stadia  is  a  compound  «  g—  v----^=m 

cross- wire  ring  or  diaphragm,         ^&&s&&^ 
as    shown    in     the 

STADIA 

cut,  having  three 
horizontal  wires,  of  which 
the  middle  one  is  attached  to 
the  ring  as  usual,  while  the 
others  are  fastened  to  slides,  held  apart  by  springs  and 
actuated  by  independent  screws,  by  which  the  distance 
between  the  two  movable  wires  can  be  adjusted  to  include 
a  given  space,  as  one  foot  on  a  rod  one  hundred  feet  distant. 
These  wires  will  in  the  same  manner  include  two  feet  on 
a  rod  two  hundred  feet  distant,  or  half  a  foot  at  a  distance  of 
fifty  feet,  and  so  on  in  the  same  proportion,  thus  furnishing  a 
means  of  measuring  distances,  especially  over  broken  ground, 
more  easily  and  even  more  accurately  than  with  a  tape  or 


10  TRANSIT-INSTRUMENTS 

chain.  Stadia  wires  are  inserted  in  all  our  transit  telescopes 
without  extra  cost,  if  requested  when  the  instrument  is 
ordered. 

The  stadia  wires  are  fixed,  when  desired,  on  the  same 
ring  with    the   cross-wires,  and   when   thus 

FIXED   STADIA  .          ,        ,  ,  .  .       , 

placed  they  are  not  adjustable,  but  are 
accurately  and  permanently  set  by  us  to  read  distances  as 
above. 

The  stadia  wires  are  usually  arranged  so  that  they  are 
seen  at  the  same  time  as  the  cross-wires.  When  desired,  we 
DISAPPEARING  place  them  so  that  they  are  out  of  focus 

STADIA  when  the  cross-wires  are  visible,  or  vice 

versa.  Many  engineers  prefer  this  method,  as  being  less 
confusing  to  the  observer  and  lessening  the  liability  of  error. 

The  increasing  use  of  the  stadia,  often  demanding  the 
measurement  of  short  distances  with  the  utmost  accuracy, 
STADIA  compels  the  use  of  the  so-called  stadia  "con- 
CONSTANT  stant"  ;  that  is,  the  wires  are  adjusted  to  read 
one  foot  on  the  rod  at  a  distance  from  the  center  of  the 
instrument  of  one  hundred  feet  plus  c  plus  /,  c  being  the 
distance  of  the  objective  from  the  center  of  the  instrument, 
found  by  measuring  from  the  center  of  the  axis  to  the 
shoulder  of  the  setting  of  the  objective  when  it  is  focused  on 
a  distant  object,  and  /  being  the  focal  length  of  the  object- 
ive, found  by  measuring  from  the  cross-wires  to  the  objective. 

The  reason  for  this  is  that  the  rays  cross  each  other  so 
that  the  vertex  of  the  visual  angle  is  not  at  the  center  of  the 
instrument,  but  at  a  distance  in  front  of  the  objective  equal 
to  its  focal  length. 

The  constant  for  each  instrument,  or  distance  of  the  zero 
of  the  indicated  distance  -in  front  of  the  center  of  the  instru- 
ment, is  noted  on  a  card  placed  in  the  instrument  box. 


TRANSIT-INSTRUMENTS  11 

For  example,  in  our  eleven -inch  telescopes,  such  as  are 
used  with  our  larger  transits,  <r  =  5.6  inches  and/ =8. 2 
inches;  ^ -f-/r=1.15  feet.  In  our  Mountain  Transit  tele- 
scopes, t  =  4  inches  and  /=  5.4  inches;  c-\-f=.  0.783 
feet.  In  our  Reconnoissance  Transit  telescopes,  r  =  4.25 
inches  and  /=  5.75  inches;  c  +/=  0.833  feet. 

This  constant  never  varies  for  any  given  instrument,  and 
is  independent  of  the  distance  itself. 

The  dust  guard  to  the  objective  slide,  as  shown  in  the  cut, 
is   placed   on    the    tele- 
DUST       scopes  of  Tran - 

GUARD        sitS     NOS.     1     tO 

90,  and  Nos.  110  to  117. 

This  guard  protects  the 

objective  slide,  and  pre-  NO.  154 

vents  any  dust  or  foreign  substance  from  interfering  with  its 

perfect  action. 

Price  of  Dust  Guard  placed  on  an  old  Transit  of  our 
manufacture $6.00 

With  the  telescope  of  the  ordinary  transit  it  is  impossible 
to  focus  on  objects  at  a  distance  of  less  than  ten  feet.  In 
SHORT  order  to  enable  the  observer  to  see  objects  near  the 
FOCUS  instrument,  we  have  recently  introduced  an  impor- 
tant modification  of  the  telescopes  used  on  our  transits,  so 
that  they  can  be  focused  on  an  object  at  a  distance  of  about 
four  and  one-half  feet  from  the  center  of  the  instrument. 

To  faciliate  the  placing  of  the  transit  precisely  under  a 

CENTER      given   point,  we   now   place   in    the   top   of   the 

POINT       ball  of  the  telescope  axis,  and  directly  over  the 

center   of  the   instrument,  a   small    conical    hole  or  center 

point. 

The  standards  of  the  transit  are  firmly  attached  by  their 


1 2  TRANSIT-  INS  Tfi  U ME  NTS 

expanded  bases  to  the  upper  plate,  one  of  them  having  near 
the  top  a  little  box,  as  shown  on  page  44, 

STANDARDS 

movable  by  a  screw  underneath,  by  which  the 
telescope  axis  is  made  precisely  horizontal,  as  described  on 
page  25. 

The  magnetic  needle  varies  in  length  in  the  different 
sizes  of  transits.  The  brass  cap  has  inserted  in  it  a  perfectly 
MAGNETIC  polished  jeweled  center  of  special  shape,  and 
NEEDLE  this,  resting  upon  the  hardened  and  polished 
point  of  the  center-pin,  allows  the  needle  to  play  freely  and 
settle  in  the  magnetic  meridian. 

The  needle  has  on  its  south  end  a  coil  of  wire,  easily 
moved  to  bring  both  ends  of  the  needle  to  the  same  level. 
A  screw  passing  through  the  upper  plate  moves  a  concealed 
lever  by  which  the  button  is  raised,  thus  lifting  the  needle 
from  the  pin  so  as  to  check  its  vibration,  or  to  bring  it  up 
against  the  glass  when  not  in  use,  avoiding  unnecessary  wear 
of  the  pivot. 

The  form  of  the  needle  is  varied  as  desired  by  the  maker 
or  surveyor,  but  is  of  two  general  classes,  one  having  the 
greatest  breadth  in  a  horizontal  direction,  the  other  in 
a  vertical.  We  usually  make  our  needles  about  eight 
one-hundredths  of  an  inch  broad,  and  about  three  one- 
hundredths  of  an  inch  thick,  with  the  ends  brought  to  a 
sharp  vertical  edge.  We  supply  other  forms,  however,  as 
desired. 

The  test  of  the  delicacy  of  a  magnetic  needle  is  the  num- 
ber of  horizontal  vibrations  which  it  will  make  in  a  certain 
arc  before  coming  to  rest.  Most  surveyors  desire  also  a 
quivering  motion  in  the  needle.  This  quality,  which  is 
manifested  more  in  a  horizontal  than  in  a  vertical  needle, 
depends  upon  the  near  coincidence  of  the  point  of  suspension 


TRANSIT- INSTRUMENTS  13 

with  the  center  of  gravity  of  the  needle,  and  merely  serves 
to  show  that  the  cap  is  unobstructed. 

The  compass  box  containing  the  needle  is  covered  by  a 
glass  to  exclude  moisture  and  air.  .  The  circle  is  silvered  and 
graduated  on  its  upper  surface  into  degrees  and  half-degrees, 
and  figured  from  0  to  90  each  way.  The  degree  marks  are 
also  cut  down  on  the  inner  edge  of  the  circle. 
VARIATION  An  arc  for  setting  off  the  magnetic  declina- 

ARc           tion    is    furnished    with    any   new   Engineers' 
Transit,  Nos.  1  to  16,  if  ordered  with  the  instrument. 
Price  of  Variation  Arc  with  new  Engineers'  Transit $4.00 

The  clamp  and  tangent  movement  has  its  tangent  screw 
with  opposing  spring  attached  to  the  upper  plate,  as 
CLAMP  AND  shown  on  page  6.  The  clamp  is  shown  in  the 
TANGENT  sectional  cut  on  page  18,  being  a  strong  metal 
ring,  D  F,  moving  easily  around  the  outer  socket,  to  which  it 
may  be  clamped  by  the  screw,  •£,  impinging  upon  a  segment, 
F.  The  plates  are  thus  held  and  moved  slowly  around  each 
other  in  either  direction  by  the  tangent  screw,  or  loosened 
and  moved  by  the  hand,  the  telescope  being  thus  easily  and 
accurately  directed  to  the  point  of  sight. 

The  two  levels  are  placed  at  right  angles  with  each  other 

so  as  to  level  the  plate  in  all  directions,  and  are  adjusted  by 

turning  the  capstan -head  nuts  at  their  ends 

PLATE  LEVELS 

by  a  steel  adjusting-pin.  The  glass  vials  used 
in  the  levels  of  all  our  transits  are  ground  on  their  inner  sur- 
face, to  give  the  bubble  an  even  motion  and  great  sensitiveness. 


14 


TRANSIT-INSTRUMENTS 


The  limbs  of  all  our  transits,  Nos.  1  to  102,  are  graduated 
on  sterling  silver,  usually  to  half-degrees,  and  read  by  vernier 
HORIZONTAL  to  one  minute.  If  desired,  the  limb  and 

LIMB  verniers  may  be  graduated  to  read  to  thirty, 

twenty,  or  ten  seconds,  but  at  an  additional  cost. 

Various  methods  of  figuring  are  used,  and  we  show 
illustrations  of  those  which  we  most  commonly  employ. 


TRANSIT-INSTRUMENTS 


15 


ILLUSTRATION  II 


ILLUSTRATION  I  —  The  figures  are  in  two  rows,  the  outer 
from  0  to  360,  and  the  inner  in  quadrants  from  0  to  90. 
This  mode  is  generally  employed  when  not  otherwise  specified. 

ILLUSTRATION  II  —  The  figures  are  in  one  row,  reading 
from  0  each  way  to  180.  This  is  the  usual  figuring  on  the 
limbs  of  Transits  Nos.  20,  100,  102,  and  105. 


16 


TRANSIT-IN^  TR  UMENTS 


ILLUSTRATION  III — The  figures  are  in  two  rows,  each 
row  from  0  to  360,  but  running  in  opposite  directions. 

ILLUSTRATION  IV  —  The  numbering  is  identical  with  that 
used  in  III,  except  that  the  figures  are  inclined  in  the 
direction  in  which  they  increase. 


TRANSIT-INSTR  UMENTS 


17 


We  will  furnish  new  transits  with  the  limbs  figured  as 
specified  by  the  purchaser,  without  extra  charge,  and  limbs 
regraduated  may  be  similarly  figured  as  directed.  Limbs 
cannot  be  refigured  without  regraduation  and  readjustment, 
the  cost  of  readjustment  being  in  addition  to  the  regular 
charge  for  regraduation,  as  noted  on  page  262. 


18 


TRANSIT-INSTR  UMENTS 


VERNIERS 


The  verniers,  V  V,  are  attached  to  the  upper  plate  dia- 
metrically opposite  each  other,  and  are  used  in  reading  the 
limb  within  which  they  revolve.  They  are 
placed  at  an  angle  of  thirty  degrees  with  the 
line  of  sight,  so  that  they  may  be  easily  read  without  a 
change  of  position.  The  vernier  openings  are  covered  with 
glass,  carefully  cemented  to  exclude  moisture  and  dust. 

The  verniers  are  double,  having  on  each  side  of  the  zero 
mark  thirty  equal  spaces  corresponding  precisely  with  twenty- 
nine  half-degrees  of  the  limb.  They  thus  read  to  single 
minutes,  and  the  number  passed  over  is  counted  in  the 
direction  in  which  the  vernier  is  moved.  Sometimes  a  finer 
reading  than  minutes  is  desired,  and  the  spaces  of  the  limb  and 
vernier  are  then  made  proportionately  less.  (See  page  14.) 

The  use  of  two  opposite  verniers  gives  the  means  of 
cross-questioning  the  graduations,  the  perfection  with  which 
they  are  centered,  and  the  accuracy  of  the  angles  indicated. 


SOCKETS  AND  CIRCULAR   PLATES 


TRANSIT-INSTRUMENTS  19 

Reflectors  of  celluloid,  as  in  the  Mountain  Transit,  are 
often   used   to   throw   white  light  upon    the 
graduations,  and   shades  of  ground  glass  are 
sometimes  used  to  give  a  more  subdued  light. 

The  graduations  were  formerly  made  on  the  brass  surface 

of  the  limb,  afterward  filled  with  black  wax  and  then  finished 

and  silvered.     The  limbs  of  all  our  transits 

GRADUATIONS  ,    '    ...  ,.  .,  rru 

are  now  covered  with  sterling  silver.  Ihe 
graduations  are  much  finer  and  more  distinct,  and  the  surface  is 
less  liable  to  become  tarnished.  This  improvement,  although 
adding  considerably  to  the  cost  of  manufacture,  we  make 
without  additional  charge. 

To  secure  the  utmost  accuracy  of  graduation  and  avoid 
any  possibility  of  molecular  change  after  the  graduation  is 
made,  the  limbs  of  our  transits  are  polished  and  the  figures 
engraved  before  cutting  the  divisions. 

The  sockets  of  the  transit  are  compound.     The  interior 

spindle  attached  to  the  vernier  plate  turns  in  the  exterior 

socket,  C,  when  an  angle  is  taken  on  the  limb ; 

but  when  the  plates  are  clamped   the   exterior 

socket  itself,  and  with  it  the  whole  instrument,  revolves  in 

the  socket  of  the  leveling-head. 

The  sockets  are  constructed  with  the  greatest  care.  They 
are  truly  concentric,  and  the  composition  of  which  they  are 
made  is  of  different  degrees  of  hardness,  causing  them  to 
move  upon  each  other  with  the  least  possible  wear. 

The  leveling-head  consists  of  two  plates  connected  by  a 
socket,  which  has  at  its  end  a  hemispherical  nut  fitting  into  a 
LEVELING-  corresponding  cavity  in  the  lower  plate.  The 
HEAD  plates  are  inclined  to  each  other  or  made 
parallel  by  .four  leveling-screws.  If  specially  ordered,  we 
make  the  leveling-head  with  three  leveling-screws. 


20  TRANSIT-INSTRUMENTS 

The  screws  are  of  bronze  and  are  fitted  to  long  nuts  in 
the  upper  leveling-plate.  They  are  protected  from  dust  by 
brass  covers  screwed  on  the  upper  ends  of  the  nuts.  The 
screws  rest  in  cups  or  sockets,  in  which  they  turn  without 
marring  the  surface  of  the  lower  plate,  the  cups  also  allowing 
the  screws  to  be  shifted  from  side  to  side,  or  turned  in  either 
direction  on  the  lower  plate. 

The  clamp  and  tangent  movement  of  the  leveling-head, 
partially  shown  on  page  6,  serves  to  turn  the  whole  instru- 
ment upon  its  sockets,  so  as  to  fix  the  telescope  with  precision 
upon  any  given  point,  or  when  undamped  allows  it  to  be 
directed  approximately  by  hand.  The  tangent  screw  is  sin- 
gle, as  shown,  and  has  an  opposing  spring  by  which  lost 
motion  is  avoided  and  a  very  delicate  and  prompt  movement 
secured. 

The  lower  leveling-plate  is  in  two  pieces,  the  upper  one, 
which  is  screwed  to  the  top  of  the  tripod,  having  a  large  open- 
ing in  the  center,  in  which  the  smaller 

SHIFTING  CENTER        .    B  ,  .,      ,    f 

lower  plate  is  shifted  from  side  to  side. 

By  this  device,  called  a  shifting  center,  the  instrument  may 
be  easily  moved  over  the  upper  plate,  and  the  plummet  which 
hangs  from  the  center,  P  (see  page  18),  may  be  set  precisely 
over  a  point  without  moving  the  tripod. 

The  tripod  has  a  head  of  bronze  with  three  strong  tenons 
to  receive  the   legs,  the  upper  ends  of  which  are 

TRIPOD  ,    _        .  ,       .  ,         -     ,  ,     . 

pressed  firmly  on  each  side  of  the  tenon  by  a  bolt 
and  nut  on  opposite  sides  of  the  leg.  This  nut  can  be 
screwed  up,  and  thus  kept  firm.  The  lower  end  of  the 
leg  has  a  brass  shoe  with  steel  point,  securely  fastened  and 
riveted  to  the  wood. 

For  various  patterns  of  tripods,  see  pages  186  to  189. 


TRANSIT- INSTRUMENTS  21 

TO    USE    THE    TRANSIT 

The  instrument  should  be  set  up  firmly,  the  tripod  legs 
being  pressed  into  the  ground,  so  as  to  bring  the  plates  as 
nearly  level  as  convenient.  The  plates  should  then  be  care- 
fully leveled  and  properly  clamped. 

For  precise  work,  in  addition  to  leveling  by  the  plate 
levels,  it  is  always  advisable,  if  the  transit  has  such  attach- 
ment, to  level  the  plates  by  the  telescope  level,  as  this  is  much 
more  sensitive  than  the  levels  on  the  plate.  In  this  operation 
the  position  of  the  level  on  telescope  must  be  observed  over 
each  pair  of  leveling-screws  in  turn,  and  one-half  the  correc- 
tion made  by  the  axis  tangent,  the  other  half  by  the  leveling- 
screws. 

Before  an  observation  is  made  with  the  telescope,  the  eye- 
piece should  be  focused  until  the  cross-wires  appear  distinct. 
The  objective  is  then  focused  until  the  object  is  seen  clear  and 
well-defined,  and  the  wires  appear  as  if  fastened  to  its  surface. 
The  intersection  of  the  wires  should  be  brought  precisely  upon 
the  object  to  which  the  telescope  is  directed. 

The  zeros  of  the  verniers  and  limb  should  be  brought  into 
line  by  the  tangent  screw  of  the  plates,  and  the  telescope 
directed  to  the  object  by  the  tangent  screw  of  the  leveling- 
head.  The  angles  taken  are  then  read  off  upon  the  limb, 
without  subtracting  from  those  given  by  the  verniers  in  any 
other  position. 

TO  ADJUST    THE    TRANSIT 

Every  instrument  should  leave  the  hands  of  the  maker  in 
complete  adjustment,  but  all  adjustments  are  so  liable  to 
derangement  by  accident  or  careless  use  that  we  consider  it 
necessary  to  describe  particularly  those  which  are  most  likely 
to  need  attention. 


22  TRANSIT-INSTRUMENTS 

The  principal  adjustments  of  the  transit  are :  the  Levels, 
the  Line  of  Collimation,  the  Standards. 

To  adjust  the  levels:    Set  the  instrument  upon  its  tripod 

as  nearly  level  as  may  be,  and  having  undamped  the  plates, 

bring  the  two  levels  above,  and  on  a  line  with,  the 

LEVELS 

two  pairs  of  leveling-screws.  Clasp  the  heads  of 
two  opposite  screws,  and,  turning  both  in  or  out,  as  may  be 
needed,  bring  the  bubble  of  the  level  directly  over  the 
screws  exactly  to  the  middle  of  the  opening.  Without 
moving  the  instrument,  proceed  in  the  same  manner  to  bring 
the  other  bubble  to  the  middle.  The  level  first  corrected 
may  now  be  thrown  a  little  out ;  if  so,  bring  it  in  again,  and 
when  both  are  in  place  turn  the  instrument  half-way  around. 
If  the  bubbles  are  both  in  the  middle  they  need  no  cor- 
rection ;  but  if  not,  turn  the  nuts  at  the  end  of  the  levels 
with  the  adjusting-pin,  until  the  bubbles  are  moved  over  half 
the  error.  Bring  the  bubbles  again  into  the  middle  by  the 
leveling-screws,  and  repeat  the  operation  until  the  bubbles 
will  remain  in  the  middle  during  a  complete  revolution  of 
the  instrument. 

To  adjust  the  line  of  collimation :  This  adjustment  is  to 
bring  the  cross-wires  into  such  a  position  that  the  instrument, 
LINE  OF  when  placed  at  the  middle  of  a  straight  line, 
COLLIMATION  w{\\}  by  the  transit  of  the  telescope,  cut  the 
extremities  of  -the  line.  Having  leveled  the  instrument, 
determine  if  the  vertical  wire  is  plumb,  by  focusing  on  a 
defined  point  and  observing  if  the  wire  remains  on  that  point 
when  the  telescope  is  elevated  or  depressed.  If  not,  loosen 
the  cross-wire  screws  and  by  their  heads  turn  the  ring-  until 
correct,  the  openings  in  the  telescope  tube  being  slightly 
larger  than  the  screws,  so  that  when  the  latter  are  loosened  the 
ring  can  be  rotated*  a  short  distance  in  either  direction. 


TRANSIT-INSTRUMENTS  23 

Direct  the  intersection  .of  the  cross-wires  on  an  object  two  or 
three  hundred  feet  distant.  Set  the  clamps  and  transit  to  an 
object  about  the  same  distance  in  the  opposite  direction. 
Unclamp,  turn  the  plates  half-way  around,  and  direct  again 
to  the  first  object ;  then  transit  to  the  second  object.  If  it 
strikes  the  same  place  the  adjustment  is  correct.  If  not,  the 
space  which  intervenes  between  the  points  bisected  in  the 
two  observations  will  be  double  the  deviation  from  a  true 
straight  line,  since  the  error  is  the  result  of  two  observations. 
In  the  diagram  below,  let  A  represent  the  center  of  the 
instrument,  and  B  C  the  imaginary  straight  line,  upon  the 
extremities  of  which  the  line  of  collimation  is  to  be  adjusted. 
B  represents  the  object  first  selected,  and  D  the  point  which 
the  wires  bisected  when  the  telescope  was  reversed. 

-D 
C 
-E 

When  the  instrument  is  turned  half  around,  and  the  tele- 
scope again  directed  to  B,  and  once  more  reversed,  the  wires 
will  bisect  an  object,  E,  situated  as  far  to  one  side  of  the  true 
line  as  the  point,  D,  is  on  the  other  side.  The  space,  D  E, 
is  therefore  the  sum  of  two  deviations  of  the  wires  from  a 
true  straight  line,  and  the  error  is  made  very  apparent. 

In  order  to  correct  it,  use  the  two  capstan -head  screws  on 
the  sides  of  the  telescope,  these  being  the  ones  which  affect  the 
position  of  the  vertical  wire.  It  must  be  kept  in  mind  that 
the  eyepiece  apparently  inverts  the  position  of  the  wires,  and 
therefore,  in  loosening  one  of  the  screws  and  tightening  the 
other  on  the  opposite  side,  the  operator  must  proceed  as  if  to 
increase  the  error  observed. 

The  wires  being  adjusted,  their  intersection  may  now  be 


24  TRANSIT-INSTRUMENTS 

brought  into  the  center  of  the  field  of  view  by  moving  the 
screws,  A  A,  shown  in  the  sectional  view  of  the  telescope  on 
page  7,  which  are  slackened  and  tightened  in  pairs,  the  move- 
ment being  now  direct,  until  the  wires  are  seen  in  their 
proper  position. 

The  position  of  the  line  of  collimation  depends  upon  that 
of  the  objective  solely,  so  that  the  eyepiece  may,  as  in  the 
case  just  described,  be  moved  in  any  direction,  or  even  re- 
moved and  a  new  one  substituted,  without  at  all  deranging  the 
adjustment  of  the  wires. 

In  case  it  becomes  necessary  to  remove  the  cross-wire  ring, 
the  operator  should  proceed  as  follows:  Take  out  the  eye- 
piece, together  with  the  ring  by  which  it  is  centered,  remove 
two  opposite  cross-wire  screws,  and  with  the  others  turn  the 
ring  until  one  of  the  screw  holes  is  brought  into  view  from 
the  open  end  of  the  telescope  tube.  In  this  screw  hole  thrust 
a  splinter  of  wood  or  a  wire,  to  hold  the  ring  when  the  remain- 
ing screws  are  withdrawn.  The  ring  can  then  be  removed. 
It  may  be  replaced  by  returning  it  to  its  position  in  the  tube, 
and  after  either  pair  of  screws  is  inserted  the  splinter  or  wire 
is  removed,  and  the  ring  is  turned  until  the  other  screws  can 
be  replaced,  care  being  taken  that  the  face  of  the  diaphragm 
is  turned  toward  the  eyepiece.  The  eyepiece  is  next  inserted, 
and  its  centering-ring  brought  into  such  a  position  that  the 
screws  in  it  can  be  replaced,  and  the  ring  into  which  the  eye- 
piece is  fixed  is  then  screwed  to  the  end  of  the  telescope. 

To  adjust  the  standards :  In  order  that  the  point  of  inter- 
section of  the  wires  may  trace  a  vertical  line  as  the  telescope 
is  elevated  or  depressed,  it  is  necessary  that 

STANDARDS  ,       ,         .      ,  ,        .  ,     .  f 

the  standards  of  the  telescope  should  be  of 
precisely  the  same  height.  To  ascertain  this,  and  make  the 
correction,  if  needed,  proceed  as  follows: 


TRANSIT-INSTRUMENTS  25 

Having  the  line  of  collimation  properly  adjusted,  set  up 
the  instrument  in  a  position  where  points  of  qbservation,  such 
as  the  apex  and  base  of  a  lofty  spire,  can  be  selected,  giving 
a  long  range  in  a  vertical  direction. 

Level  the  instrument,  direct  the  telescope  to  the  top  of 
the  object,  and  clamp  to  the  spindle ;  then  bring  the  tele- 
scope down  until  the  wires  bisect  some  well-defined  point  at 
the  base.  Turn  the  instrument  half  around,  direct  the  tele- 
scope to  the  lower  point,  clamp  to  the  spindle,  and  raise  the 
telescope  to  the  highest  point.  If  the  wires  bisect  it,  the 
vertical  adjustment  is  effected ;  if  they  are  thrown  to  either 
side,  this  proves  that  the  standard  opposite  to  that  side  is  the 
highest,  the  apparent  error  being  double  that  actually  due  to 
this  cause.  To  correct  it,  we  make  one  of  the  bearings  of 
the  axis  movable,  so  that  by  turning  a  screw  underneath  this 
sliding  piece,  as  well  as  the  screws  which  fasten  the  cap  of 
the  standard,  the  adjustment  is  made  with  the  utmost  precision. 

Besides  the  three  adjustments  described,  which  are  all  that 
the  surveyor  will  ordinarily  be  required  to  make,  there  are 
other  adjustments  of  the  transit  which  may  sometimes  be 
necessary. 

In  case  of  accident  or  injury  it  may  be  necessary  to  adjust 
the  objective  slide,  and  this  should  be  done  as  follows :  Hav- 
OBJECTIVE  mg  set  UP  and  leveled  the  instrument,  the  line 
SLIDE  Of  collimation  being  adjusted  for  objects  from 
three  hundred  to  five  hundred  feet  distant,  clamp  the  plates, 
and  fix  the  vertical  cross-wire  upon  an  object  as  distant  as 
may  be  distinctly  seen.  Without  disturbing  the  instrument,' 
move  out  the  objective  so  as  to  bring  the  vertical  wire  upon 
an  object  as  near  as  the  range  of  the  telescope  will  allow. 
Having  this  clearly  in  mind,  loosen  the  upper  clamp,  turn  the 
instrument  half-way  around,  reverse  the  telescope,  clamp  the 


26  TRANSIT-INSTRUMENTS 

instrument,  and  with  the  tangent  screw  bring  the  vertical  wire 
again  upon  the  near  object ;  then  draw  in  the  objective  until 
the  distant  object  first  sighted  upon  is  brought  into  distinct 
vision.  If  the  vertical  wire  strikes  the  same  line  as  at  first, 
the  slide  is  correct  for  both  near  and  remote  objects,  and, 
being  itself  straight,  for  all  distances. 

But  if  there  is  an  error,  proceed  as  follows:  With  a  screw- 
driver turn  the  two  screws,  C  C  (see  page  7),  on  the  opposite 
sides  of  the  telescope,  loosening  one  and  tightening  the  other, 
so  as  to  apparently  increase  the  error,  making,  by  estimation, 
one-half  the  correction  required.  Then  go  over  the  usual 
adjustment  of  the  line  of  collimation,  and,  having  completed 
it,  repeat  the  operation  above  described,  first  sighting  upon 
the  distant  object,  then  upon  a  near  one  in  line,  then  revers- 
ing, making  corrections,  etc.,  until  the  adjustment  is  com- 
plete. 

This  adjustment  is  peculiar  to  our  transits,  and  furnishes 
the  only  way  in  which  the  line  of  collimation  can  be  made 
correct  for  all  distances. 

The  adjustments  of  the  vertical  circle  and  the  level  on 
telescope  are  described  on  pages  55  to  60. 


ENGINEERS'  TRANSIT 


E  circular  plates  of  the  Engineers'  Transit,  with  their 
sockets,  are  shown  in  section  on  page  18.  The  upper 
plate,  A  A,  carrying  the  compass  circle,  is  screwed  to  the 
flange  of  the  interior  spindle;  the  lower  plate  or  divided 
limb,  B,  is  fastened  to  the  exterior  socket,  C,  which  again 
is  fitted  to  and  turns  in  the  hollow  socket  of  the  leveling- 
head. 

The  long  sockets  of  the  transit  are  supported  in  the 
leveling-head,  which  is  secured  to  the  sockets  by  a  screw  and 
washer  underneath. 

The  engraving  on  page  29  shows  some  of  the  attach- 
ments often  used  with  the  transit ;  the  vertical  arc,  level  on 
ATTACHMENTS  telescope,  and  clamp  and  tangent  to  tele- 
TO  TRANSITS  scope  axis  with  gradienter  screw.  These 
and  other  attachments  are  used  where  leveling,  taking  vertical 
angles,  etc.,  must  be  done  in  connection  with  the  ordinary 
work  of  the  transit,  and  the  attachments  and  their  adjust- 
ments are  described  on  pages  54  to  77. 

We  make  three  sizes  of    the  Engineers'  Transit,  having 
SIZES  AND      needles   respectively   four,  four  and   one-half, 
WEIGHTS       and  five  inches  long.     The  average  weight  of 
each  size,  with  plain  telescope,  is  as  follows : 

4-inch  needle,  about 12£  Ibs. 

4^-inch  needle,  about 14    Ibs. 

5-inch  needle,  about 16    Ibs. 

The  tripod  furnished  with  this  transit  weighs  between 
nine  and  ten  pounds. 

28 


OP 

UNIVERSITY 


OF 


NO.  16 


Engineers'  Transit,  two  verniers  to  limb,  5-inch  needle,  with  6-inch  vertical  arc  with  ver- 
nier moved  by  tangent  screw  and  reading  to  30  seconds,  level  on  telescope, 
gradienter  combined  with  clamp  and  tangent,  and  tripod. 
Price,  as  shown,  $198.00. 

29 


30  ENGINEER'S  TRANSIT 

The  diameter  of  the  limb  of  each  size  is  as  follows : 

4-inch  needle •. .5.65  inches 

4^-inch  needle 6.25  inches 

5-inch  needle 6.70  inches 

When  it  is  necessary  to  separate  the  plates  of  the 
Engineers'  Transit,  proceed  as  follows:  Unscrew  the  nut 
which  confines  the  spring  in  the  thimble  opposed  to  the 
tangent  screw  on  the  upper  plate ;  take  out  the  three  screws 
which  fasten  the  tangent  fixture  to  the  upper  plate ;  and 
remove  the  screw  and  washer  underneath,  which  secure  the 
sockets  to  the  leveling-head.  The  plates  can  then  be  readily 
separated.  To  put  the  transit  together  again,  the  operation 
should  be  exactly  reversed. 

ENGINEERS'  TRANSIT  WITH  SOLAR 
ATTACHMENT 

The  engraving  on  page  31  represents  our  Engineers' 
Transit  with  five-inch  needle  and  attachments  of  vertical  arc 
of  three  inches  radius,  graduated  on  silver  and  reading  to 
thirty  seconds,  level  on  telescope,  clamp  and  tangent  to  tele- 
scope axis,  and  solar  apparatus  with  declination  arc  reading  to 
thirty  seconds.  Platinum  stadia  wires  are  always  furnished 
with  this  instrument,  unless  otherwise  ordered. 

The  horizontal  limb  is  graduated  on  sterling  silver  and 
reads  to  single  minutes.  If  ordered  with  the  instrument,  the 
compass  circle  is  made  movable  with  rack  and  pinion,  for 
setting  off  the  magnetic  declination. 

Price  of  Variation  Arc  with  new  Engineers'  Transit.   $  4.00 
Price  of  Variation  Arc  added  to  any  Engineers'  Tran- 
sit sent  to  us  for  addition  of  Solar  Attachment. ...      15.00 


NO.    17 


ENGINEERS'    TRANSIT,  WITH  SOLAR   ATTACHMENT 

Price,  as  shown,  $250.00. 


EXPLORERS'  TRANSIT 


'T'HIS  instrument  is  designed  to  supply  the  demand  for  a 
•*•  transit  of  greatest  accuracy  with  the  least  possible  weight. 
In  pattern  similar  to  our  Light  Mountain  Transit,  the  instru- 
ment itself  weighs  only  about  five  pounds,  and  when  placed 
in  its  leather-covered  case  can  be  readily  packed  and  carried 
in  a  twenty-four-inch  dress-suit  case. 

The  telescope  is  six  and  one-half  inches  long,  with  a  power 
of  about  ten  diameters,  and  can  be  focused  on  an  object  three 
feet  from  the  center  of  the  instrument.  The  attachments  of 
vertical  circle  four  inches  in  diameter,  graduated  on  silver 
and  reading  to  one  minute,  figured  from  0  to  90  each  way, 
level  on  telescope,  and  clamp  and  tangent  to  telescope  axis, 
are  furnished  with  the  transit. 

The  needle  is  two  and  three-quarters  inches  long,  and  the 
compass  plate  is  arranged  with  a  variation  arc  for  setting  off 
the  magnetic  declination. 

The  horizontal  limb  is  four  inches  in  diameter,  graduated 
on  silver,  and  reads  by  two  opposite  double  verniers  to  one 
minute.  Unless  otherwise  ordered,  the  limb  is  figured  in  one 
row  from  0  to  180.  The  leveling-head  is  of  ribbed  pattern, 
with  shifting  center,  and  has  dust  caps  to  the  leveling- 
screws. 

The  instrument  is  packed  in  a  leather-covered  wood  box, 
which  has  lock  and  key,  shoulder  strap,  plummet,  reading 
glass,  and  the  usual  small  accessories. 

A  special  extension  tripod,  with  pointed  legs  and  canvas 
carrying  case,  is  usually  furnished ;  but  an  extension  tripod, 
similar  to  that  used  with  the  Light  Mountain  Transit,  can  be 

32 


EXPLORERS'    TRANSIT 


33 


NO.  20 

.EXPLORERS'  TRANSIT 
Price,  as  described,  $165.00. 


34 


EXPLORERS*    TRANSIT 


substituted,  if  desired,  at  a  reduction  of  five  dollars  from  the 
price  of  the  instrument  as  described. 

The  weight  of  the  tripod  is  about  five  pounds  and  the 
instrument  box  weighs  about  four  pounds,  making  the  weight 
of  the  complete  outfit  thirteen  pounds. 


The  Explorers'  Transit  in  its  box  and  the  tripod  with  the  jointed  legs  in  its  case  can  be 
packed  and  carried  in  an  ordinary  24-inch  dress-suit  case,  as  shown. 

If  desired,  we  can  furnish  a  good  leather  dress-suit  case  for  $8.00  extra. 


LIGHT  MOUNTAIN  TRANSIT 


E  Light  Mountain  Transit,  introduced  by  us  in  1876  to 
meet  a  demand  for  a  light  instrument  of  the  finest  quality, 
has  met  with  a  very  large  sale  and  has  been  universally  ap- 
proved. It  is  especially  fitted  for  mine  or  mountain  surveying, 
where  great  portability  is  essential,  but  is  equally  adapted  to 
the  general  work  of  the  engineer.  The  instrument,  shown 
on  page  36,  has  a  needle  four  inches  long,  and  a  telescope 
eight  inches  long  with  a  power  of  twenty  diameters.  Plati- 
num stadia  wires  are  always  furnished  with  this  instrument, 
unless  otherwise  ordered. 

The  sockets  are  like  those  shown  on  page  18.  The  com- 
pass circle  is  movable  about  its  center,  sp  as  to  set  off  the 
magnetic  decimation. 

The  limb  has  a  diameter  of  five  and  sixty-five  hundredths 
inches,  and  is  graduated  on  silver,  reading  usually  to  single 
minutes;  but,  if  desired,  it  can  be  graduated  to  read  to 
twenty  or  thirty  seconds.  There  are  caps  above  the  leveling- 
screws  to  exclude  dust. 

The  cut  shows  the  celluloid  reflectors,  placed  over  the  two 
opposite  verniers  of  the  limb  to  .throw  light  upon  the  gradua- 
tions below,  which  are  of  special  convenience  in  the  surveys 
of  mines. 

The  Mountain  Transit  is  sometimes  used  with  a  plain  tele- 
scope, but  oftener  with  one  or  more  attachments,  as  vertical 
ATTACHMENTS  arc>  level  and  clamp  and  tangent,  as  shown. 
FOR  TRANSITS  Frequently  this  instrument  is  furnished  as 
shown  on  page  37,  with  vertical  arc,  level,  clamp  and  tangent, 
and  solar  attachment. 

35 


36 


MOUNTAIN  TRANSIT 


NO.  28 

Light  Mountain  Transit,  two  verniers  to  limb,  4-inch  needle,  with  vertical  arc,  level 
telescope,  and  clamp  and  tangent  to  telescope  axis,  and  extension  tripod. 
Price,  $186.00. 


MOUNTAIN  TRANSIT 


37 


NO.  30 

Light  Mountain  Transit,  two  verniers  to  limb,  4-inch  needle,  with  solar  attachment 

vertical  arc  reading  to  1  minute,  level  on  telescope,  and  clamp  and  tangent 

to  telescope  axis,  and  extension  tripod.     Price,  $245.00. 


38  'MOUNTAIN  TRANSIT 

The  Light  Mountain  Transit  is  almost  always  used  upon 
our  improved  extension  tripod  (see  page  189),  the  legs  of 
which  can  be  lengthened  or  shortened  at  will.  It  is  thus 
adapted  for  use  in  mountain  surveys,  where  one  or  more  legs 
must  be  shortened,  or  for  use  in  mines,  where  a  short  tripod 
is  often  indispensable. 

The  sliding  pieces  can  be  turned  end  for  end,  the  points 
being  thus  out  of  the  way  and  the  tripod  more  easily  trans- 
ported.    The  tripod  when  closed  is  only  three  feet  long,  and 
is  carried  by  a  shawl  strap,  which  we  furnish  with  it. 
LEATHER  Besides  the  light  mahogany  box,  in  which  the 

CASE         instrument  is  packed  as  usual,  there  is  also  sup- 
plied a  sole-leather  case,  furnished  with  shoulder  straps. 

The  weight  of   this  instrument  with  plain  telescope  and 

without  tripod  is  ten  pounds ;    with  solar  attachment,  vertical 

arc,  level  and  clamp,  as  shown  in  the  cut  on  page 

WEIGHT 

37,  twelve  pounds.     The  extension  tripod  weighs 
about  eight  and  one -half  pounds. 


SURVEYORS'  TRANSIT 

WITH  TWO  VERNIERS  TO  THE  HORIZONTAL  LIMB 


nr^HE  Surveyors'  Transit  with  two  verniers  to  limb  has 
essentially  the  same  construction  as  the  Engineers'  Transit, 
but  its  compass  circle  is  movable  about  its  center,  like  that 
of  the  Mountain  Transit,  in  order  that  the  magnetic  declina- 
tion may  be  set  off  in  the  surveys  of  old  lines,,  or  in  running 
lines  by  the  true  meridian. 

The  arrangement  of  the  sockets  and  leveling -head  permits 
the  Surveyors'  Transit  to  be  detached  from  the 

SOCKETS        .         ,.         ,7 

levelmg-head   and   replaced    upon    its    spindle, 
when  desired,  without  disturbing  its  adjustments. 

The  sectional  view  (page  41)  shows  the  interior  construc- 
tion of  the  sockets  of  the  transit,  the  manner  in  which  it  is 
detached  from  its  spindle,  and  the  means  by  which  it  can  be 
taken  apart. 

In  the  figure  the  limb,  B,  is  attached  to  the  main  socket, 
C,  which  is  itself   fitted   to  the  conical 

HORIZONTAL  LIMB  .  . 

spindle,  H,  and  held  in  place  by 
the  spring  catch,  S. 

The  upper  plate,  A,  carrying  the  compass  circle,  stand- 
ards, etc.,  is  fastened^  to  the  flange  of  the  socket,  K,  which 
is  fitted  to  the  upper  conical  surface  of  the  main  socket,  C, 
the  weight  of  all  the  parts  being  supported  on  the  small  bear- 
ings of  the  end  of  the  socket,  as  shown,  so  as  to  turn  with  the 
least  possible  friction. 

A  small  conical  center,  in  which  a  screw  is  inserted  from 
below,  is  brought  down  firmly  upon  the  upper  end  of  the 
main  socket,  C,  thus  holding  the  two  plates  of  the  instrument 

39 


40 


NO.  47 


Surveyors'  Transit,  two  verniers  to  limb,  5-inch  needle,  with  4%-inch  vertical  circle  with 

vernier  to  1  minute,  level  on  telescope,  clamp  and  tangent  to  telescope 

axis,  and  tripod.     Price,  $160.00. 


SURVEYORS'    TRANSIT 


41 


securely  together,  and  at  the  same  time  allowing  them  to  move 
freely  around  each  other  in  use.  A  disk  above  the  conical 
center  contains  the  steel  center-pin  upon  which  rests  the 
needle,  as  shown,  the  disk  being  fastened  to  the  upper  plate 
by  two  screws. 

The  clamp  to  limb,  with  clamp  screw,  is  also  shown  at 
D  F,  attached  to  the  main  socket  below. 

The  main  socket,  with  all  its  parts,  is  of  the  best  bell 
metal,  and  is  most  carefully  and  thoroughly  made,  the  long 
bearing  of  the  sockets  insuring  their  firm  and  easy  movement, 
while  at  the  same  time  they  are  entirely  out  of  reach  of  dust 
or  other  source  of  wear. 

When  desired,  the  whole  upper  part  of  the  instrument  may 
be  taken  off  from  the  spindle  by  pulling  out  the  head  of  the 


SOCKETS  AND  CIRCULAR   PLATES 


42  *       .SURVEYORS'    TRANSIT 

spring  catch  at  S,  and  when  replaced  will  be  secured  by  the 
self-acting  spring  of  the  catch. 

The  figure  also  shows  the  covers  of  the  leveling-screws, 
the  shifting  center  of  the  lower  leveling-plate,  and  the  screw 
and  loop  for  the  attachment  of  the  plummet. 
SIZES  AND  The   sizes   and  weights   of   the   Surveyors' 

WEIGHTS       Transit  with  two  verniers  to  limb,  and  having 
plain  telescope,  are : 

4-in.  needle,  with  leveling-head,  but  no  tripod,  about  13|  Ibs. 
5-in.  needle,    "         "  "  "         "          "      16  J  Ibs. 

5f  in.  needle,  "         "  "  "      17J  Ibs. 

The  diameter  of  the  limb  of  each  size  is  as  follows: 

4-inch  needle '. 5.65  inches 

5-inch-  needle 6. 70  inches 

5^-inch  needle 7.20  inches 

When  it  is  necessary  to  separate  the  plates  of  this  transit, 
proceed  as  follows  (  see  page  41  ) :  Unscrew  the  milled-head 
cap  from  the  thimble  containing  the  opposing  spring  of  the 
tangent  movement  to  limb,  and  take  out  the  three  screws 
which  fasten  that  movement  to  the  upper  plate.  Remove  the 
clamp  screw  of  the  variation  arc  and  take  off  the  head  of  the 
pinion,  both  outside  the  compass  circle.  Unscrew  the  bezel 
ring  holding  the  glass  cover  of  the  compass,  remove  the 
needle  and  button  beneath  it,  and  take  out  the  two  screws,  to 
remove  the  disk.  Take  the  instrument  from  its  spindle,  and 
with  a  screw-driver  take  out  the  screw  from  the  under  side  of 
the  conical  center,  and  drive  out  the  center  from  below  by  a 
round  piece  of  wood,  holding  the  instrument  so  that  the 
center  will  not  bruise  the  circle.  The  plates  can  then  be 
separated.  To  put  the  transit  together  again,  the  operation 
should  be  exactly  reversed. 


SURVEYORS'  TRANSIT 

WITH  ONE  VERNIER  TO  THE  HORIZONTAL  LIMB 


^T^HE  Surveyors'  Transit  with  one  vernier  to  limb  is  a  modi- 
fication  of  the  instrument  just  described,  in  which  there  is 
but  one  double  vernier  to  limb  and  a  different  arrangement  of 
the  sockets,  as  shown  in  the  sectional  cut  on  page  45. 

The  instrument  is  more  compact  and  somewhat  lighter 
than  that  with  two  verniers,  and  is  furnished  at  less  cost.  Its 
graduations,  telescope,  and  attachments  are  equal  to  those 
of  the  more  costly  transits  ;  and  after  an  experience  of  more 
than  forty  years  the  instrument  has  proved  itself  satisfactory 
for  all  classes  of  work. 

The  adjustments  and  use  of  this  instrument  are  like  those 
of  the  others  already  described,  and  its  attachments  to  the 
telescope  the  same,  if  desired. 

It  is  represented  in  the  cut  with  a  level  on  telescope  and 
clamp  and  tangent  to  telescope  axis.  (See  page  44.) 

The  sectional  cut  shows  the  arrangement  of  the  sockets  of 
this  instrument.  The  spindle,  C,  is  fitted  to  the 

SOCKETS 

socket  of  the  levehng-head,  and  connected  there- 
with by  a  screw  and  washer  underneath,  as  in  the  figure. 

The  socket,  K,  is  formed  in  the  metal  of  the  upper  plate, 
a  strong  washer  with  four  screws,  only  two  of  which  are  seen 
in  the  cut,  keeping  the  two  plates  together,  at  the  same  time 
allowing  them  to  turn  freely  around  each  other. 

The  clamp  to  limb,  with  clamp  screw,  is  shown  in  dotted 
lines  at  D  F,  under  the  plates. 

The  vernier  with  the  opening  above  is  shown  on  the  left 
at  A.  The  arrangement  of  the  center-pin,  needle,  etc.,  is 

43 


44 


NO.  76 


Surveyors'  Transit,  one  vernier  to  limb,  5-inch  needle,  with  level  on  telescope,  clamp 

and  tangent  to  telescope  axis,  and  tripod. 

Price,  $133.00. 


SURVEYORS'    TRANSIT 


45 


like  that  of  the  transit  with  two  verniers,  but  the  instrument 
remains  attached  to  the  leveling-head  like  the  Engineers' 
Transit. 


SOCKETS  AND  CIRCULAR  PLATES 

SIZES  AND  The   sizes   and   weights  of   the    Surveyors' 

WEIGHTS       Transit  with  one  vernier  to  limb,  and  having 
plain  telescope,  are  : 

4-in.  needle,  with  leveling-head,  but  no  tripod,  about  13  Ibs. 
5-in.  needle,     "         "  "  "          "  "      16  Ibs. 

6J-in.  needle,  "         "  "  "          "  "      17  Ibs. 

The  diameter  of  the  limb  of  each  size  is  as  follows : 

4-inch  needle 5.65  inches 

5-inch  needle .0.70  inches 

5^-inch  needle 7.20  inches 

To  take  apart  the  Surveyors'  Transit  with  one  vernier  to 
limb :  Unscrew  the  milled-head  cap  of  the  tangent  opposing 
spring,  and  take  out  the  three  screws  which  secure  the  tangent 
support  to  the  upper  plate.  Remove  the  pinion  head  and 


46  SURVEYORS'    TRANSIT 

clamp  screw  near  the  compass  circle ;  unscrew  the  bezel  ring, 
take  out  the  needle  and  button  underneath,  and  remove  the 
disk  in  which  the  center-pin  is  fixed,  b'y  taking  out  two  screws 
which  hold  it.  Remove  the  four  screws  which  hold  the 
washer  to  the  under  plate,  and  the  plates  can  be  easily  sepa- 
rated. The  several  parts  are  replaced  in  the  reverse  order. 

SURVEYORS'   TRANSIT   WITH  SOLAR  ATTACH- 
MENT 

The  engraving  on  page  47  represents  our  Surveyors' 
Transit  with  five-inch  needle  and  with  two  verniers  to  the 
horizontal  limb,  to  which  is  added  the  solar  attachment,  with 
vertical  arc,  level  on  telescope,  and  clamp  and  tangent  to 
axis  of  telescope.  Both  the  vertical  arc  and  the  arc  of  the 
declination  arm  are  graduated  on  silver,  and  read  by  vernier 
to  thirty  seconds. 

The  solar  attachment  may  be  used  upon  the  transit  with 
two  verniers  to  limb  or  with  one  vernier  to  limb,  as  preferred. 
Both  instruments  are  provided  with  shifting  center  to  the 
leveling-head.  Platinum  stadia  wires  are  furnished  with 
every  solar  instrument,  unless  otherwise  ordered. 

The  Surveyors'  Transit  having  one  vernier  to  the  limb 
has  sockets  as  shown  on  page  45,  and  when  fitted  with  the 
solar  attachment  is  listed  as  No.  90. 

PRICES 

No. 

60  Surveyors'  Transit,  two  verniers  to  limb,  5-inch  needle, 
with  Solar  Attachment,  vertical  arc  of  3  inches  radius, 
level  on  telescope,  clamp  and  tangent  to  telescope  axis, 
and  tripod $226.00 

90  Surveyors'  Transit,  one  vernier  to  limb,  5-inch  needle,  with 
Solar  Attachment,  vertical  arc  of  3  inches  radius,  level 
on  telescope,  clamp  and  tangent  to  telescope  axis,  and 
tripod.  .< 211.00 


NO.  60 


SURVEYORS'   TRANSIT  WITH   SOLAR  ATTACHMENT 


RECONNO1SSANCE  TRANSIT 


TN  response  to  a  demand  for  a  very  light  transit  for  rapid 
•*•  work,  where  extreme  accuracy  is  not  required,  we  intro- 
duced in  1887  the  Reconnoissance  Transit,  as  shown  on  page 
49.  This  instrument  is  finished  with  the  same  care  as  our 
larger  and  more  expensive  transits,  and  we  recommend  it  as 
a  reliable  instrument  for  a  great  variety  of  work.  The  quality 
of  the  instrument,  together  with  its  portability,  have  made  it 
very  popular. 

It  has  a  needle  three  and  one-half  inches  in  length,  a 
limb  four  and  nipety-six  hundredths  inches  in  diameter,  grad- 
uated on  silver  and  reading  by  one  double  vernier  to  single 
minutes,  and  a  spring  tangent  movement  like  the  larger  in- 
struments. The  limb  is  figured  from  0  to  180,  unless  other- 
wise ordered. 

The  telescope  is  nine  inches  long  and  has  a  power  of  from 
eighteen  to  twenty  diameters.  It  has  a  long  level,  vertical 
circle  reading  to  five  minutes,  and  clamp  and  tangent  to  axis. 
The  objective  is  focused  by  a  rack  and  pinion  and  the  eye- 
piece by  a  spiral  movement.  Platinum  stadia  wires  are  always 
furnished  with  this  instrument,  unless  otherwise  ordered. 

The  compass  circle  is  arranged  to  set  off  the  magnetic 
declination,  the  movement  being  made  by  a  pinion. 

The  instrument  has,  as  shown,  a  leveling-head  with  shift- 
ing center,  and  with  spring  clamp  and  tangent,  and  it  is  used 
upon  our  light  extension  tripod,  the  legs  of  which  close  up  to 
about  three  feet  in  length. 

The  weight  of  this  transit  without  the  tripod  is  about 
seven  and  three-quarters  pounds ;  complete  with  tripod,  about 
fifteen  pounds. 

48 


RECONNOISSANCE    TRANSIT 


49 


No. 
100 


102 


NOS100  PRICE 
Reconnoissance  Transit,  one  vernier  to  limb,  8|-inch  needle, 
with  3-J-inch  vertical  circle  with  vernier  reading  to  five 
minutes,   level  on  telescope,  clamp  and  tangent  to  tele- 
scope axis,  and  leveling  tripod  with  extension  legs $115.00 


Reconnoissance  Transit,  same  as  No    100,  but  with  4 .1 -inch 
vertical  circle  with  vernier  reading  to  one  minute 


122.00 


BUILDERS'  TRANSIT 


>T*HE  Builders'  Transit,  shown  on  page  51,  is  an  instru- 
ment  devised  for  use  in  the  construction  of  buildings 
where  it  is  necessary  not  only  to  furnish  levels,  but  to  de- 
termine points  in  a  vertical  plane  above  or  below  the  level 
line,  or  on  either  side  and  in  line  with  the  center  of  the 
instrument,  more  conveniently  than  can  be  done  with  the 
Architects'  Level.  This  transit  has  a  telescope  with  long 
graduated  level,  clamp  and  tangent  to  axis,  a  graduated  limb 
reading  by  an  index  to  one  degree  and  figured  from  0  to  180 
each  way,  clamp  and  tangent  to  both  limb  and  leveling-head, 
shifting  center,  plain  tripod,  and  trivet  plate. 

In  use,  the  instrument  is  set  either  upon  the  tripod  or  trivet, 
and  the  plates  are  accurately  leveled  by  the  two  levels  shown. 

If  it  is  desired  to  run  a  level  line,  the  bubble  of  the  tele- 
scope level  is  brought  into  the  middle  by  the  clamp  and 
tangent  of  the  axis,  in  which  position  the  hori- 

LEVEL   LINE 

zontal  wire  of  the  telescope  will  determine  a 

level  line,  as  in  the  telescope  of  the  ordinary  level,  and  any 

horizontal  angle  to  one  degree  may  be  read  off  upon  the  limb. 

When  necessary  to  obtain  points  in  a  vertical  plane,  either 

VERTICAL     above  or  below  a  given  point,  the  plates  should 

LINE          be  clamped  and  the  clamp  of  the  telescope  axis 

released,  when  the  telescope  may  be  directed  either  above  or 

below  to  the  point  desired. 

To  determine  two  points  in  a  straight  line  with  the  instru- 

STRAIGHT      ment  and  on  opposite  sides  of  its  center,  direct 

L!NE          the  telescope  to  one  of  the  points,  clamp  the 

plates,  and  obtain  the  other  point  by  reversing  the  telescope 

upon  its  axis. 

50 


BUILDERS'    TRANSIT 


51 


The  weight  of  the  Builders'  Transit  is  about  seven  pounds  ; 
with  tripod  complete,  about  thirteen  pounds. 


NO.   105 

Builders'  Transit,  with  level  on  telescope,  clamp  and  tangent  to  telescope  axis,  limb  and 

spindle,  and  with  leveling-screws  and  tripod. 

Price,  $80.00. 


VERNIER  TRANSIT  COMPASS 


>"lpHIS  instrument,  shown  on  page  53,  is  essentially  a  ver- 
A  nier  compass  with  a  telescope  instead  of  the  sight  vanes, 
thus  giving  the  surveyor  the  means  of  taking  long  sights, 
either  on  a  level  or  on  hilly  ground,  with  ease  and  accu- 
racy. 

The  telescope  is  eleven  inches  in  length  and  of  fine 
quality,  and  may  be  fitted  with  attachments  as  shown,  and 
levels  and  angles  of  elevation  and  depression  can  be  taken 
as  with  the  more  expensive  instruments. 

The  compass  circle  is  moved  about  its  center  by  a  pinion 
placed  above  the  circular  plate,  and  the  magnetic  declination 
is  set  off  to  single  minutes  upon  a  graduated  arc  attached  to 
the  plate,  as  shown  in  the  cut.  There  is  also  a  clamp  screw, 
by  which  the  circle  may  be  made  secure. 

The  figure  represents  the  instrument  with  six-inch  needle. 
In  the  smaller  size  the  vernier  of  the  compass  circle  is  within 
the  box  and  under  the  glass,  as  in  the  Surveyors'  Transit. 
The  needle-lifting  screw  is  underneath  the  plate,  but  is  not 
shown  in  the  cut. 

The  clamp  screw,  by  which  the  instrument  is  fixed  to  the 
spindle,  and  the  spring  catch  which  secures  it,  are  both  shown, 
on  opposite  sides  of  the  socket. 

The  levels  are  both  above  the  plate,  and  are  adjustable  by 
capstan -head  nuts  at  either  end. 

This  instrument  is  commonly  used  on  a  ball -spindle 
placed  in  a  compass  tripod,  as  shown  on  page  53;  but  it  is 
sometimes  fitted  to  a  leveling-head,  like  that  shown  on 
page  132. 

52 


VERNIER    TRANSIT  COMPASS 


53 


We  make  two  sizes  of  this  instrument,  having  needles 
SIZES  AND  respectively  five  and  six  inches  in  length.  The 
WEIGHTS  average  weights  are  as  follows: 

5-inch  needle,  plain  telescope,  and  without  tripod,    9    Ibs. 
6-inch  needle,      "  "  "          "  "       llf  Ibs. 


NO.   117 

Vernier  Transit,  6-inch   needle,  with  3^-inch  vertical  circle  with   vernier  reading  to  5 

minutes,  level  on  telescope,  clamp  and  tangent  to  telescope  axis,  and  tripod. 

Price,  $101.00. 


ATTACHMENTS   FOR  TRANSITS 


TN  the  use  of  the  transit  it  is  generally  found  advisable  to 
add  one  or  more  attachments  to  the  telescope.  All  our 
transits  and  their  attachments  are  now  made  to  standard  sizes, 
so  that  one  or  more  of  these  useful  accessories  can  be  fitted 
to  the  instrument  at  any  time  without  -  additional  expense 
other  than  the  cost  of  the  attachment  itself. 

When  any  of  these  attachments  are  desired,  either  for  our 
instruments  or  those  of  other  makers,  it  is  best  to  send  the 
instrument  to  us.  In  some  cases  they  can  be  added  by  a 
skillful  mechanic  nearer  the  customer,  but  this  is  generally 
more  expensive  and  less  satisfactory. 

The  principal  attachments  for  the  transit  are : 

VERTICAL  CIRCLE  (see  pages  55-57). 

VERTICAL  ARC  (see  page  58). 

LEVEL  ON  TELESCOPE  (see  page  59). 

CLAMP  AND  TANGENT  to  Telescope  Axis  (see  pages  59  and  61). 

SIGHTS  ON  TELESCOPE  (see  page  61). 

SIGHTS  ON  STANDARDS  for  Right  Angle  Observation  (see  page  61). 

ATTACHED  MAGNIFIERS  to  Horizontal  Limb  (see  page  61). 

BEAMAN  STADIA  ARC  (see  page  62). 

GRADIENTER,  combined  with  Clamp  and  Tangent  (see  page  64). 

DETACHABLE  TELESCOPES  for  Vertical  Sighting  (see  page  66). 

REFLECTOR  for  Illuminating  the  Cross-Wires  (see  page  67). 

DIAGONAL  PRISM  for  Eyepiece  of  Telescope  (see  page  67). 

PLUMMET  LAMP  (see  page  68). 

SOLAR  ATTACHMENT  to  Telescope  (see  pages  69-77). 

SOLAR  SCREEN  (see  page  89). 


51 


ATTACHMENTS  FOR    TRANSITS 
VERTICAL   CIRCLE 


55 


NO.    136 


The  vertical  circle  is  graduated  on  silver  and  figured  from 
0  to  90.  Three  sizes  are  generally  used,  the  three  and  one- 
half-inch  circle  reading  by  vernier  to  five  minutes,  as  shown 
in  No.  117  (page  53),  the  four  and  one-half -inch  circle  reading 
by  vernier  to  single  minutes,  as  shown  in  No.  136,  and  the 
five-inch  circle  reading  by  vernier  to  single  minutes. 

To  adjust  the  vertical  circle :  Having  the  instrument 
firmly  set  up  and  carefully  leveled,  bring  into  line  the  zeros 
of  the  circle  and  vernier,  and  with  the  tele- 
scope find  some  well-defined  point,  from  one 
hundred  to  five  hundred  feet  distant,  which  is  cut  by  the 
horizontal  wire.  Turn  the  instrument  half-way  around,  tran- 
sit the  telescope,  and  fixing  the  wire  upon  the  same  point  as 
before,  observe  if  the  zeros  are  again  in  line.  If  not,  loosen 
the  capstan -head  screws  which  fasten  the  vernier,  and  move 
the  zero  of  the  vernier  over  half  the  error;  bring  the  zeros 


ADJUSTMENT 


56 


ATTACHMENTS  FOR    TRANSITS 


again  into  coincidence,  and  proceed  exactly  as  before,  until 
the  error  is  entirely  corrected. 

In  most  cases  the  error  is  slight  and  may  be  best  removed 
by  putting  the  zeros  in  line  and  making  the  adjustment  by  the 
horizontal  wire,  moving  it  by  the  vertical  capstan-head  screws 
until  the  vertical  circle  will  reverse  on  the  same  point. 


NO.    138 

VERTICAL  CIRCLE   WITH   OPPOSITE  VERNIERS 

The  five-inch  vertical  circle  may  be  arranged  as  shown  in 
No.  138,  to  be  read  by  two  opposite  double  verniers  to  one 
minute.  The  verniers  are  supported  on  a  ribbed  frame 
fastened  with  the  circle  to  a  flange  in  such  a  manner  that  the 
circle  is  concentric  with  the  frame,  and  the  verniers  read 
accurately  in  any  position  of  the  circle. 

The  frame  is  arranged  with  an  adjusting-screw,  to  bring 
the  verniers  into  exact  adjustment  with  the  level  on  tele- 
scope. 


ATTACHMENTS  FOR    TRANSITS  57 

PRICES   OF  VERTICAL   CIRCLES 
No. 

135  3£-inch  Vertical  Circle .V, $  8.00 

136  4|-inch       "           "       12.00 

137  5  -inch       "           "       15.00 

138  5  -inch       "           "       with  two  opposite  double  verniers  ...  35.00 


NO.   141 

ALUMINUM  GUARD  FOR  VERTICAL  CIRCLE 
Price,  $6.00. 

For  protecting  the  graduated  edge  of  the  vertical  circle 
we  make  an  improved  guard,  as  shown  in  No.  141.  This 
guard  is  of  aluminum,  finely  finished,  and  so  mounted  on  the 
standard  as  to  be  concentric  with  the  circle.  We  can  furnish 
this  guard  for  all  sizes  of  vertical  circles  which  we  make. 


58  ATTACHMENTS  FOR    TRANSITS 

VERTICAL  ARC 


NOS.    139   AND   140 

Price,  $18.00 

The  vertical  arc  is  made  in  two  sizes,  of  two  and  one -half 
and  three  inches  radius, 'graduated  on  silver  and  read  by  a 
vernier  swung  from  the  axis  and  movable  by  a  tangent  screw. 

The  arc  is  movable  around  its  bearing  on  the  axis,  and 
can  be  readily  clamped  at  zero  with  the  vernier  in  any  posi- 
tion of  the  telescope,  and  any  degree  of  elevation  can  be  read 
off  directly  on  the  arc. 

The  arc  of  two  and  one-half  inches  radius  is  generally  used 
on  the  Light  Mountain  Transit,  and  reads  by  its  vernier  to 
single  minutes,  while  the  arc  of  three  inches  radius  is  com- 
monly used  on  the  larger  transits,  and  reads  by  the  vernier  to 
thirty  seconds.  The  vertical  arc  can  be  readily  attached  to 
any  transit  of  our  manufacture. 


ATTACHMENTS  FOR    TRANSITS  59 

LEVEL   ON   TELESCOPE  AND   CLAMP  AND 
TANGENT   TO    TELESCOPE  AXIS 


NOS.    145  AND   148 

Price  of  Level  on  Telescope,  $12.00. 

The  level  on  telescope,  No.  145,  consists  of  a  brass  tube 
about  six  and  one -half  inches  long,  each  end  of  which  is  held 
between  two  capstan  nuts  connected  with  a  screw  or  stem 
attached  to  the  under  side  of  the  telescope  tube. 

The  vial  enclosed  in  the  tube  is  a  little  over  five  inches 
long  and  half  an  inch  in  diameter,  and  is  ground  on  its  inner 
surface  so  as  to  insure  an  even  and  sensitive  bubble,  the 
length  of  which  is  measured  by  the  scale  above.  The  scale 
is  graduated  to  tenths  of  an  inch,  and  is  figured  from  0  at  the 
middle  to  5,  10,  15,  on  either  side,  thus  determining  when 
the  bubble  is  brought  into  the  middle  of  its  run. 

To  adjust  the  level  on  telescope :  When  the  vernier  of 
the  vertical  circle  is  adiusted,  as  on  pa^e  55, 

ADJUSTMENT  f          ...          . 

and    is    at   zero,  the    line  ol    colhmation   is 
level  and  the  bubble  may  be  brought  into  the  middle  of  its 


60  ATTACHMENTS  FOR    TRANSITS 

run  by  the  capstan -head  nuts.  Another  method  is  as  follows : 
•  First  level  the  instrument  carefully,  and  with  the  clamp  and 
tangent  movement  to  the  axis  make  the  telescope  as  nearly 
horizontal  as  may  be,  by  the  eye.  Then,  having  previously 
adjusted  the  line  of  collimation,  drive  a  stake  at  a  convenient 
distance,  say  from  one  hundred  to  three  hundred  feet,  and 
note  the  height  cut  by  the  horizontal  wire  upon  a  staff  set  at 
the  top  of  the  stake. 

Fix  another  stake  in  the  opposite  direction  and  at  the  same 
distance  from  the  instrument,  and  without  disturbing  the  tele- 
scope turn  the  instrument  upon  its  spindle,  set  the  staff  upon 
the  stake,  and  drive  the  stake  into  the  ground  until  the  same 
height  is  indicated  as  in  the  first  observation.  The  top  of  the 
two  stakes  will  then  be  in  the  same  horizontal  line,  however 
much  the  telescope  may  be  out  of  level. 

Remove  the  instrument  from  fifty  to  one  hundred  feet'  to 
one  side  of  either  of  the  stakes  and  in  line  with  both.  Again 
level  the  instrument,  clamp  the  telescope  as  nearly  horizontal 
as  may  be,  and  note  the  heights  indicated  upon  the  staff 
placed  first  upon  the  nearest  and  then  upon  the  most  distant 
stake.  If  both  agree,  the  telescope  is  level.  If  they  do  not 
agree,  with  the  tangent  screw  move  the  wire  over  nearly  the 
whole  error,  as  shown  at  the  distant  stake,  and  repeat  the 
operation  just  described.  Proceed  thus  until  the  horizontal 
wire  will  indicate  the  same  height  at  both  stakes,  when  the 
telescope  will  be  truly  horizontal.  Taking  care  not  to  disturb 
the  position  of  the  telescope,  bring  the  bubble  into  the  middle 
by  the  little  leveling-nuts  at  the  end  of  the  tube,  when  the 
adjustment  will  be  complete. 


ATTACHMENTS  FOR    TRANSITS 


61 


CLAMP  AND    TANGENT 

Price,  $6.00 

The  clamp  and  tangent,  No.  148,  consists  of  an  arm  at 
one  end  encircling  the  telescope  axis,  and  at  the  other  end 
connected  with  the  tangent  screw.  The  clamp  is  fastened  at 
will  to  the  axis  by  a  clamp  screw  inserted  at  one  side  of  the 
ring,  and  by  turning  the  tangent  screw  the  telescope  may  be 
raised  or  lowered. 

The  clamp  and  tangent  must  always  accompany  the  verti- 
cal circle  and  level  on  telescope,  whenever  either  is  used  on  a 
transit. 

SIGHTS  ON   TELESCOPE  AND   ON  STANDARDS 

For  convenience  in  observation,  we  occasionally  place  a 
pair  of  small  sights  on  the  telescopes  of  our  transits.  These 
sights  have  folding  joints,  that  they  may  lie  close  to  the  tele- 
scope when  not  in  use.  Sights  may  also  be  placed  on  the 
standards  at  an  angle  of  ninety  degrees  with  the  telescope,  for 
use  in  offsetting. 

Price  of  either  pattern,  per  pair $8.00 

ATTACHED  MAGNIFIERS 

Attached  magnifiers 
are  frequently  used  over 
the  verniers  of  the  hori- 
zontal or  vertical  limb, 
and  are  held  by  a  universal 
three-jointed  arm,  which 
allows  the  lens  to  be  placed 
over  any  point  of  the 
vernier. 

Price  of  Attached  Magnifiers,  each $5.00 


62 


ATTACHMENTS  FOR    TRANSITS 

SEAMAN  STADIA  ARC 
Patented  March  27,  iqob 


NO.    149 

This  new  and  specially  graduated  vertical  arc  furnishes 
engineers  with  a  rapid  and  exact  mechanical  solution  of  the 
stadia  problem,  since  by  its  use  precise  differences  in  eleva- 
tion, and  reduced  horizontal  distances,  can  be  determined  with 
great  rapidity,  without  the  use  of  any  of  the  adjuncts  in 
stadia  surveying  heretofore  necessary. 

This  arc  was  devised  in  1904  by  W.  M.  Beaman,  a 
topographer  in  the  U.  S.  Geological  Survey,  and  is  now 
extensively  used  by  that  bureau  in  its  topographical  surveys. 
It  can  replace,  or  be  attached  to,  the  vertical  arc  of  any 
instrument. 

The  Beaman  stadia  arc  has  two  scales :  a  multiple  scale, 
V,  by  the  use  of  which  the  grade  per  hundred  feet  of 
observed  stadia  distance  may  be  determined,  and  a  reduc- 
tion scale,  H,  giving  the  percentage  of  correction  necessary 


ATTACHMENTS  FOR    TRANSITS  63 

to    reduce    observed    stadia    distance     to     true     horizontal 
distance. 

We  furnish  this  stadia  arc  attached  to  the  vertical  limbs 
of  new  transits  or  telescopic  alidades,  or  fit  it  to  any  instru- 
ment sent  to  us  for  that  purpose.  The  price  of  the  arc,  when 
fitted  to  an  old  instrument,  will  depend  on  the  cost  of  attach- 
ing, and  will  be  quoted  after  examination  of  the  instrument. 

ADVANTAGES  OF    THE  STADIA   ARC 

1.  The   use   of  stadia   tables,    slide-rules,    or   diagrams   is   entirely 
obviated. 

2.  There  is  no  vernier  or  similar  .contrivance  to  be  read. 

3.  Final  results  are  obtained  in  less  than  one-third  the  time  required 
by  ordinary  methods. 

4.  The  accuracy  of  results  is  identical  with  formulae  or  table  compu- 
tations, regardless  of  the  angle  or  distance. 

5.  The  simplicity  of  the  process  practically  eliminates  the  chances  of 
error  incidental  to  the  use  of  other  methods. 

A  more  detailed  description  of  the  Beaman  stadia  arc 
and  its  use,  as  well  as  a  general  discussion  of  the  subject  of 
stadia  surveying,  is  found  in  the  special  pamphlet  on  Stadia 
Surveying  which  we  publish,  and  which  we  furnish  free  of 
charge  on  application. 


64 


ATTACHMENTS  FOR    TRANSITS 
GRADIENTER 


NO.   150 

Price,  as  shown,  $18.00. 

This  attachment  is  often  used  with  the  transit  for  deter- 
mining distances,  fixing  grades  and  similar  work. 

It  consists  mainly  of  a  screw  attached  to  the  expanded 
arm  of  the  ordinary  clamp  of  the  telescope  axis.  This  screw 
is  accurately  cut,  and,  passing  through  a  nut  in  one  side  of  the 
arm,  presses  against  a  stud,  A,  fixed  to  the  inside  surface  of 
the  right-hand  standard.  In  the  side  of  the  arm  opposite 
the  screw  is  an  enclosed  spiral  spring  which  presses  against 
the  side  of  the  stud,  thus  securing  a  positive  movement  of  the 
gradienter  screw. 

Near  the  other  end  of  the  screw,  and  turning  with  it,  is  a 


ATTACHMENTS  FOR    TRANSITS  65 

wheel  or  micrometer,  the  rim  of  which  is  covered  with  silver, 
and  graduated  into  one  hundred  equal  parts.  A  silver  scale, 
attached  to  the  arm  and  just  above  the  micrometer  wheel,  is 
graduated  into  spaces,  each  of  which  is  equal  to  one  revolu- 
tion of  the  screw ;  so  that  by  comparing  the  edge  of  the 
wheel  with  the  graduations  of  the  scale,  the  number  of  com- 
plete revolutions  of  the  screw  can  be  easily  counted. 

When  the  clamp  is  made  fast  to  the  axis,  the  gradienter 
screw  will  serve  as  an  ordinary  tangent  screw  to  incline  the 
MEASURING  telescope.  As  the  value  of  its  screw  thread  is 
DISTANCES  such  that  a  complete  revolution  of  the  screw 
will  move  the  horizontal  cross-wire  of  the  telescope  over  a 
space  of  one  foot  on  a  vertical  rod  at  a  distance  of  one 
hundred  feet,  it  is  clear  that  when  the  screw  is  turned  through 
fifty  spaces  on  the  graduated  head,  the  wire  will  pass  over 
fifty-hundredths,  or  one -half  a  foot  on  the  rod,  and  so  on  in 
the  same  proportion.  In  this  way  the  gradienter  can  be  used 
in  the  measurement  of  distances. 

To  avoid  any  possibility  of  error,  it  is  advisable  that 
observations  should  not  be  taken  by  a  reversal  of  the  screw. 

Grades  can  be  established  with  great  facility  as  follows : 

Level  the  instrument,  and  bring  the  telescope  level -bubble  to  the 

middle  by  the  clamp  and  gradienter  screw.      Move 

GRADES 

the  graduated  head  until  its  zero  is  brought  to  the 
edge  of  the  scale ;  then  turn  off  as  many  spaces  on  the  head 
as  there  are  hundredths  of  feet  to  the  hundred  in  the  grade  to 
be  established. 


66 


ATTACHMENTS  FOR   TRANSITS 


DETACHABLE    TELESCOPES  FOR    VERTICAL 
SIGHTING 


NO.  161 


A  convenient 
arrangement  for 
sighting  up  or 
down  a  vertical 
shaft  is  shown  in 
No.  160,  in 
which  an  extra 
telescope  is 
fitted  with  a 
flange  and  disk 
connecting  it 
with  the  axis, 
so  as  to  make  it 
precisely  paral- 
1  e  1  with  t  h  e 
main  telescope. 
A  counterpoise, 
as  shown,  is 


ATTACHMENTS  FOR    TRANSITS 


67 


fitted  to  the  other  end  of  the  axis,  and  both  telescope  and 
counterpoise  can  be  detached  and  placed  in  the  transit  box 
when  not  in  use. 

In  No.  161,  the  extra  telescope  is  connected  with  the 
main  telescope  by  coupling-nuts,  which  fasten  it  directly  over 
the  center  of  the  instrument  and  allow  its  ready  removal  and 
replacement  without  disturbing  its  adjustments.  In  both 
arrangements  the  extra  telescope  is  adjusted  to  the  main  tele- 
scope of  the  transit  so  that  the  lines  of  collimation  of  both  are 
parallel  and  in  the  same  plane,  horizontal  in  No.  160  and  vertical 
in  No.  161  ;  and  in  both  the  extra  telescope  swings  over  the 
outside  of  the  transit  plates.  The  diagonal  prism  is  often  used 
with  the  extra  telescope  for  greater  convenience  in  sighting. 

Price  of  either  Telescope,  No.  160  or  No.  161 $25.00 

The  reflector,  Nos.  165  and  166, 
is  an  elliptical  piece  of  silver  inclined 
at  an  angle  of  forty-five 
degrees   with    its   ring, 
which  is  fitted  to  the  objective  end  of 
the  telescope.     The   opening   in    the 
reflector  allows    the  use    of  the    tele- 
scope, while  a  light  held  near  the  inner 
surface    illuminates     the    cross-wires. 
(See  page  275.) 

The  diagonal  prism,  No.  168,  is  used 
when  it  is  necessary  to   observe  greater 
DIAGONAL   vertical  angles  than  can  be 
PRISM       taken  with  the  ordinary  tele- 
scope.     It  consists  of  a  prism  attached 
to  the  cap  of  the  eyepiece,  by  which  the 
object  is  presented  to  the  eye  when  placed 
at  right  angles  with  the  telescope.      When 


REFLECTOR 


NOS.  165    AND   166 

REFLECTOR 
Prices,  §4.00  and  $5.00. 


68  ATTACHMENTS  FOR   TRANSITS 

the  telescope  is  directed  to  the  sun  the  slide  or  darkener  con- 
taining colored  glass  is  moved  over  the  opening. 

The  circular  plate  to  which  the  prism  is  attached  is  made 
to  turn  in  the  cap,  so  that,  when  it  is  substituted  for  the  ordi- 
nary cap  of  the  eyepiece,  the  opening  of  the  prism  can  be 
easily  adjusted  to  the  position  of  the  eye.  Observations  can  be 
taken  with  the  prism  up  to  an  angle  of  sixty  degrees  elevation. 
The  Plummet  Lamp,  No.  170,  is  a  large 
PLUMMET  plummet,  of  which  the  upper 
LAMP  part  is  hollow  to  contain  oil. 
It  has  a  tube  for  a  wick,  and  an  extin- 
guisher. 

It  is  hung  in  gimbals  by  chains  with  a 
.  hook,    and    so    always   assumes   a    vertical 
position,    and    when    suspended    from    the 
shifting  center  of  a  leveling-head  it  can  be 
easily  adjusted  over  a  given  point. 

These  lamps  are  packed  in  a  wooden 
case,  furnished  with  a  strap  to  sling  over 
the  shoulders.  The  weight  of  each  lamp  is 
about  one  and  one-quarter  pounds,  and 
either  one,  two,  or  three  may  be  packed  in 
each  box,  as  desired. 


NO.    170 

PLUMMET  LAMP 
Price,  $10.00 


SOLAR  ATTACHMENT 


NO.   190 

Price,  $60.00. 

E  solar  attachment  is  essentially  the  solar  apparatus  of 
Burt  placed  upon  the  cross-bar  of  the  transit.  A  disk 
one  and  one -half  inches  in  diameter,  having  a  pivot  project- 
ing above  its  upper  surface,  is  screwed  to  the  telescope  axis. 
Upon  this  pivot  rests  the  enlarged  base  of"  the  polar  axis, 
which  is  firmly  connected  with  the  disk  by  four  capstan -head 
screws  passing  from  the  under  side  of  the  disk  into  the  base. 
These  screws  serve  to  adjust  the  polar  axis,  as  will  be 
explained  hereafter. 

69 


70  SOLAR  ATTACHMENT 

The  hour  circle  surrounding  the  base  of  the  polar  axis  is 

easily  movable  about  it,  and  can  be  fastened  at  any  point 

desired  by  two  flat -head  screws  above.     It  is 

HOUR   CIRCLE  _  .  r      •  •     r- 

graduated  to  five  minutes  of  time,  is  figured 
from  I  to  XII,  and  is  read  by  an  index  fixed  to  the  declina- 
tion arc  and  moving  with  it.  A  hollow  cone  or  socket,  fitting 
the  polar  axis  and  made  to  move  upon  it,  or  to  be  clamped  at 
any  point  desired  by  a  milled-head  screw  on  top,  furnishes  by 
its  arms  below  a  firm  support  for  the  declination  arc,  which  is 
fastened  to  it. 

The  declination  arc  has  a  radius  of  about  five  inches,  and 
is  graduated  to  quarter -degrees.  On  the  Mountain  Transit  it 
DECLINATION  reads  by  its  vernier  to  single  minutes,  and  on 
ARC  the  larger  transits  to  half-minutes,  the  gradu- 

ations of  both  vernier  and  limb  being  in  the  same  plane.  The 
declination  arc  has  the  usual  lenses  and  silver  plate  on  the  two 
opposite  blocks,  also  a  clamp  and  tangent  movement,  as 
shown  in  the  cut.  The  arc  of  the  declination  limb  is  turned 
on  its  axis  and  one  or  the  other  solar  lens  used,  as  the  sun  is 
north  or  south  of  the  equator.  The  cut  shows  its  position 
when  the  sun  is  north. 

The  latitude  is  set  off  by  means  of  a  large  vertical  limb 

figured  from  the  center  each  way  in  two  rows,  from  0  to  80 

and  from  90  to  10,  the  first  series  being  in- 

LATITUDE    ARC  ,     ,  ,. 

tended  for  reading  vertical  angles,  and  the 
second  series  for  setting  off  the  latitude.  The  vernier  of  the 
vertical  limb  is  made  movable  by  the  tangent  screw  attached, 
so  that  its  zero  and  that  of  the  limb  are  readily  made  to  coin- 
cide when,  in  adjusting  the  limb  to  the  level  of  the  telescope, 
the  arc  is  clamped  to  the  axis. 

The  usual  tangent  movement  to  the  telescope  axis  serves 
to    incline  the  telescope  to    the  proper  angle,  as  hereafter 


SOLAR  ATTACHMENT  71 

described.  A  level  on  the  under  side  of  the  telescope,  with 
ground  vial  and  a  scale,  is  indispensable  in  the  use  of  the  solar 
attachment.  The  arcs,  verniers,  and  hour  circle  are  all  gradu- 
ated on  silver. 

See  pages  97  to  102  for  definitions  of  astronomical  terms. 

EXPLANATION  OF    THE  SOLAR  ATTACHMENT 

In  the  engraving  on  page  72  we  have  a  graphic  illustra- 
tion of  the  solar  apparatus,  the  circles  shown  representing 
those  supposed  to  be  drawn  upon  the  concave  surface  of  the 
heavens. 

When  the  telescope  is  set  horizontal  by  its  spirit  level,  the 
hour  circle  will  be  in  the  plane  of  the  horizon,  the  polar  axis 
will  point  to  the  zenith,  and  the  zeros  of  the  vertical  arc  and 
its  vernier  will  coincide.  If  we  incline  the  telescope,  directed 
north  as  shown  in  the  cut,  the"  polar  axis  will  descend  from 
the  direction  of  the  zenith.  The  angle  through  which  it 
moves,  being  laid  off  on  the  vertical  arc,  will  be  the  co-lati- 
tude of  the  place  where  the  instrument  is  used,  the  latitude 
itself  being  found  by  subtracting  this  number  from  ninety 
degrees. 

When  the  sun  passes  above  or  below  the  equator,  its 
declination,  or  angular  distance  from  it,  as  given  in  the 
Ephemeris,  can  be  set  off  upon  the  declination  arc,  and  its 
image  brought  into  position  as  before. 

In  order  to  do  this,  however,  it  is  necessary  not  only  that 
the  latitude  and  declination  be  correctly  set  off  upon  their 
respective  arcs,  but  also  that  the  instrument  be  moved  in 
azimuth  until  the  polar  axis  points  to  the  pole  of  the  heavens, 
or,  in  other  words,  is  placed  in  the  plane  of  the  meridian. 
Thus  the  position  of  the  sun's  image  will  indicate  not  only 
the  latitude  of  the  place,  the  declination  of  the  sun  for  the 


72 


SOLAR  ATTACHMENT 


GRAPHIC  ILLUSTRATION  OF  THE  SOLAR  APPARATUS 


SOLAR  ATTACHMENT  73 

given  hour,  and  the  apparent  time,  but  it  will  also  determine 

the  meridian,  or  true  north  and  south  line  passing  through  the 

place  where  the  observation  is  made. 

The  interval  between  two  equatorial 
lines,  cc,  as  well  as  between  the  hour 
lines,  bb,  is  just  sufficient  to  include  the 
circular  image  of  the  sun,  as  formed,  by 

the  solar  lens  on  the  opposite  end  of  the  revolving  arm. 

Allowance  for  declination :    Let  us   now 

DECLINATION 

suppose  the  observation  made  when  the  sun 
has  passed  the  equinoctial  point,  and  when  its  position  is 
affected  by  declination. 

By  referring  to  the  Ephemeris,  and  setting  off  on  the  arc 
the  declination  for  the  given  day  and  hour,  we  are  still  able 
to  determine  its  position  with  the  same  certainty  as  if  it 
remained  on  the  equator. 

When  the  sun's  declination  is  south,  that  is,  from  the  22d 
of  September  to  the  20th  of  March  in  each  year,  the  arc  is 
turned  downward,  or  toward  the  plates  of  the  transit,  while 
during  the  remainder  of  the  year  the  arc  is  turned  from  the 
plates. 

When  the  solar  attachment  is  accurately  adjusted  and  the 
transit  plates  precisely  horizontal,  the  latitude  of  the  place 
and  the  declination  of  the  sun  for  the  given  day  and  hour 
being  set  off  on  their  respective  arcs,  and  the  instrument  set 
approximately  north  by  the  magnetic  needle,  the  image  of 
the  sun  cannot  be  brought  between  the  equatorial  lines  until 
the  polar  axis  is  placed  in  the  plane  of  the  meridian  of  the 
place,  or  in  a  position  parallel  with  the  axis  of  the  earth. 
The  slightest  deviation  from  this  position  will  cause  the  image 
to  pass  above  or  below  the  lines,  and  thus  discover  the 'error. 

From  the  position  of  the  sun  in  the  solar  system  we  thus 


74  SOLAR  ATTACHMENT 

obtain  a  direction  absolutely  unchangeable,  from  which  to 
run  lines  and  measure  horizontal  angles. 

This  simple  principle  is  not  only  the  basis  of  the  construc- 
tion of  solar  instruments,  but  it  is  the  sole  cause  of  their  supe- 
riority over  instruments  having  only  the  magnetic  needle. 
For  in  an  instrument  having  a  magnetic  needle,  the  accuracy 
of  the  horizontal  angles  indicated,  and  therefore  of  all  the 
observations  made,  depends  upon  the  delicacy  of  the  needle 
and  the  constancy  with  which  it  assumes  a  certain  direction, 
called  the  magnetic  meridian. 

The  principal  causes  of  error  in  the  needle  are  the  dulling 

of  the  pivot  and  the  resulting  injury  to  the  jeweled  center, 

loss  of  polarity  in  the  needle,  the  influ- 

ERROR   IN    NEEDLE  ,   .         . 

ence  of  local  attraction,  and  the  effect 
of  the  sun's  rays  producing  the  diurnal  variation.  From  all 
these  imperfections  the  solar  instrument  is  free. 

The  latitude  of  the  place  and  the  declination  of  the  sun 
being  set  off  upon  their  respective  arcs,  we  are  able  not  only 
to  run  the  true  meridian,  or  a  due  east  and  west  course,  but 
also  to  set  off  horizontal  angles  with  minuteness  and  accuracy 
from  a  direction  which  never  changes  and  which  is  unaffected 
by  attraction. 

ADVANTAGES  OF   THE  SOLAR  ATTACHMENT 

From  what  has  been  said,  the  surveyor  will  readily  under- 
stand that  the  more  perfect  horizon  obtained  by  the  use  of  the 
telescope  level,  and  the  use  of  a  telescope  in  place  of  sights, 
render  the  attachment  more  accurate  than  the  Solar  Compass. 
The  attachment  can  be  added  to  the  telescope  of  any 
good  transit  at  a  comparatively  small  cost,  thus  enabling  the 
surveyor  to  establish  the  true  meridian,  to  determine  the 
correct  latitude,  and  to  obtain  true  time  very  nearly. 


SOLAR  ATTACHMENT  75 

Its  adaptation  to  the  purposes  of  illustration  and  instruc- 
tion in  practical  astronomy  in  colleges  and  schools  will  occur 
to  every  teacher;  and  it  furnishes  for  the  government  sur- 
veyor a  long-sought  and  much -needed  instrument,  superior  to 
the  Solar  Compass  formerly  used. 

In  experiments  made  by  us,  an  error  of  one-quarter  of  a 
minute  in  the  direction  of  the  true  meridian,  or  in  latitude, 
could  be  easily  detected  by  observing  the  sun's  image  through  a 
magnifier,  and  we  feel  confident  that  any  one  who  uses  the 
solar  attachment  will  be  satisfied  with  its  work. 

The  weight  of  the  solar  attachment  is  but  little  more  than 
ten  ounces,  and  is  so  distributed  as  not  to  disturb  the  counter- 
poise of  the  instrument,  thus  obviating  the  objection  which 
has  hitherto  prevented  the  successful  use  of  the  telescope  with 
the  solar  apparatus.  When  not  in  use  the  attachment  should 
be  removed  from  the  telescope  and  packed  in  the  instrument 
case,  and  the  thin  sheath  put  on  the  polar  axis  and  kept  in  its 
place  by  the  screw  and  washer  of  the  socket. 

It  is  evident  that  all  transits  to  which  the  solar  attachment 
is  to  be  added  should  have  a  horizontal  limb  and  verniers, 
and  should  be  furnished  with  a  level  on  telescope,  clamp  and 
tangent  to  telescope  axis,  and  vertical  arc  and  vernier.  They 
should  also  have  a  movable  compass  circle  to  set  off  the  mag- 
netic declination,  and  should  be  leveled  by  leveling-screws. 
They  must  be  in  perfect  order,  especially  in  respect  to  the 
sockets,  before  correct  work  can  be  done. 


76  SOLAR  ATTACHMENT 

TO  RUN  LINES    WITH   THE  SOLAR  ATTACH- 
MENT 

Having  set  off  the  latitude  of  the  place  on  the  vertical  arc, 
and  the  declination,  corrected  for  refraction,  for  the  given 
day  and  hour  as  computed  from  the  tables  in  the  Solar 
Ephemeris,  the  instrument  being  also  carefully  leveled  by  the 
telescope  bubble,  set  the  horizontal  limb  at  zero  and  clamp 
the  plates.  Loosen  the  lower  screw  so  that  the  transit  moves 
easily  upon  its  lower  socket,  set  the  instrument  approximately 
north  and  south,  with  the  objective  end  of  the  telescope 
toward  the  north,  turn  the  proper  solar  lens  to  the  sun,  and, 
with  one  hand  on  the  plates  and  the  other  on  the  revolving 
arm,  move  them  from  side  to  side  until  the  sun's  image  is 
brought  between  the  equatorial  lines  on  the  silver  plate. 

The  lower  clamp  of  the  instrument  should  now  be  fastened, 
and  any  further  lateral  movement  be  made  by  the  tangent 
screw  of  the  leveling-head.  The  telescope  will  now  be  in  the 
true  meridian,  and  may  be  used  like  the  sights  of  the  Solar 
Compass,  but  with  far  greater  accuracy  and  satisfaction  in 
establishing  meridian  lines.  When  the  upper  or  vernier  plate 
is  undamped  from  the  limb,  an  angle  read  by  the  verniers  is 
an  angle  from  the  meridian ;  and  thus  parallels  of  latitude  or 
any  other  angles  from  the  true  meridian  may  be  established, 
as  with  the  Solar  Compass. 

The  bearing  of  the  needle,  when  the  telescope  is  on  the 
meridian,  will  also  give  the  magnetic  declination  at  the  point 
of  observation. 

.  If  the  instrument  has  a  movable  compass  circle,  as  in  our 
Surveyors'  Transits,  the  magnetic  declination  can  be  set  off  to 
single  minutes,  the  needle  kept  at  zero,  or  with  the  sun,  and 
lines  be  run  by  the  needle  alone  when  the  sun  is  obscured. 


SOLAR  ATTACHMENT  77 

REFRACTION  IN  DECLINATION 
The  Table  of  Refractions  on  pages  78  to  82  is  calculated 
for  latitudes  between  2^°  and  70°  at  intervals  of  2^°,  that 
being  as  near  as  is  required. 

The  declination  ranges  from  0°  to  20°  both  north  and 
south,  the  -f-  declinations  being  north  and  the  —  south,  and 
is  given  for  every  5°,  that  being  sufficiently  near  for  all  prac- 
tical purposes.  The  hour  angle  in  the  first  column  indicates 
the  distance  of  the  sun  from  the  meridian  in  hours,  the  refrac- 
tion given  for  0  hours  being  that  which  affects  the  observed 
declination  of  the  sun  when  on  the  meridian,  commonly 
known  as  meridional  refraction.  The  refraction  for  the  hour 
just  before  or  after  noon  is  so  nearly  that  of  the  meridian  that 
it  may  be  called  and  allowed  as  the  same. 

When  the  table  is  used,  it  must  be  borne  in  mind  that 
when  the  declination  is  north,  or  -f-  in  the  table,  the  refrac- 
tion is  to  be  added ;  when  the  declination  is  south,  or  — ,  the 
refraction  must  be  subtracted.  '  It  will  be  noticed  that  the 
refraction  in  south,  or  — ,  declination  increases  very  rapidly 
as  the  sun  nears  the  horizon,  showing  that  observations  should 
not  be  taken  with  the  sun  when  it  is  south  of  the  equator,  less 
than  one  hour  from  the  horizon. 


78 


REFRACTIONS  IN  DECLINATION 


A   TABLE  OF  MEAN  REFRACTIONS  IN 
DEC  LIN  A  TION 

To  apply  on  the  declination  arc  of  solar  attachment  of 
either  compasses  or  transits. 

Computed  by  EDWARD  W.  ARMS,  C.  E.,  for  W.  &  L.  E.  GURLEY,  Troy,  N.  Y. 


HOUR  ANGLE 

DECLINATIONS 

FOR  LATITUDE  2°  3(X 

+20° 

+15° 

+10° 

+5° 

0° 

—5° 

—10° 

-15° 

—20° 

0  h. 
2 
3 
4 
5 

—18" 
—18 
—17 
—15 
—10 

—12" 
—12 
—11 
—10 
—05 

—07" 
—07 
—06 
—05 
0 

—02" 
—02 
—01 
0 
+05 

+02" 
+02 
+03 
+05 
10 

07" 
07 
08 
10 
15 

12" 
12 

!! 

20 

18" 
18 
19 

21 
26 

23" 
23 
25 

27 
32 

FOR  LATITUDE  5° 


0  h. 

—15" 

—10" 

—05" 

0" 

+05" 

10" 

15" 

20" 

27" 

2 

—15 

—10 

—05 

0 

+05 

10 

15 

20 

27 

3 

—13 

—08 

—03 

+02 

07 

12 

17 

23 

29 

4 

—10 

—05 

0 

+05 

10 

15 

20 

27 

32 

5 

—05 

0 

+05 

10 

15 

20 

27 

32 

40 

FOR  LATITUDE  7°  30' 


0  h. 

—13" 

—08" 

—02" 

+02" 

08" 

13" 

18" 

24" 

29" 

2 

—12 

—07 

—01 

+03 

09 

14 

19 

25 

31 

3 

—10 

—05 

0 

+05 

10 

15 

20 

26 

32 

4 

—05 

0 

+05 

10 

15 

20 

26 

32 

39 

5 

-f07 

12 

17 

23 

29 

36 

43 

51 

I'Ol 

FOR  LATITUDE  10° 


0  h. 

—10" 

—05" 

0" 

+05" 

10" 

15" 

20" 

26" 

32" 

?. 

—07 

—03 

+02 

07 

12 

17 

22 

28 

34 

3 

—05 

0 

+03 

08 

13 

19 

25 

31 

38 

4 

0 

05 

10 

15 

20 

26 

32 

39 

46 

5 

+  15 

20 

26 

32 

39 

46 

55 

1'06 

1'19 

FOR  LATITUDE  12°  30' 


0  h. 

—08" 

—02" 

+02" 

8" 

13" 

18" 

24" 

30" 

36" 

2 

—06 

00 

+05 

10 

15 

20 

26 

32 

39 

3 

+02 

07 

12 

17 

23 

29 

36 

43 

51 

4 

04 

09 

14 

20 

25 

31 

40 

48 

55 

5 

21 

27 

33 

40 

48 

57 

1'08 

1'23 

1'41 

REFRACTIONS  IN  DECLINATION 


79 


HOUR  ANGLE 

DECLINATIONS 

FOR  LATITUDE  15° 

+20° 

+15° 

+10° 

+5° 

0° 

—5° 

—10° 

—15° 

—20° 

0  h. 
2 
3 
4 
5 

—05" 
—03 
+01 
08 
29 

0" 
+02 
05 
12 
34 

+05" 
07 
11 
19 
41 

10" 
12 
16 
24 

49 

15" 
18 
22 
30 
59 

21" 
23 
28 
37 
I'lO 

27" 
29 
34 
44 

1'24 

33" 
36 
41 
53 
1'43 

40" 
43 
49 
1'04 
208 

FOR  LATITUDE  17°  30' 


0  h. 

-02" 

+02" 

08" 

13" 

18" 

24" 

30" 

36" 

44" 

?, 

0 

05 

10 

15 

21 

27 

33 

40 

48 

3 

+02 

10 

15 

21- 

27 

33 

40 

48 

57 

4 

13 

18 

23 

29 

35 

43 

51 

I'Ol 

1'13 

5 

34 

41 

49 

58 

no 

1'23 

1'41 

206 

242 

FOR  LATITUDE  20° 


0  h. 

0* 

05" 

10" 

15" 

21" 

27" 

33" 

40" 

48" 

2 

03 

07 

13 

18 

24 

30 

36 

44 

52 

3 

06 

13 

18 

24 

30 

36 

44 

52 

1'02 

4 

17 

22 

28 

35 

42 

50 

I'OO 

I'll 

126 

5 

39 

47 

57 

1'07 

1'20 

1'37 

200 

232 

325 

FOR  LATITUDE  22°  30' 


0  h. 

02" 

08" 

13" 

18" 

24" 

30" 

36" 

44" 

52" 

2 

06 

11 

15 

21 

27 

33 

40 

48 

57 

3 

11 

15 

21 

27 

33 

40 

48 

57 

1'08 

4 

20 

26 

32 

39 

46 

56 

1'07 

1'19 

137 

5 

45 

53 

1'03 

1'16 

1'31 

1'52 

221 

307 

428 

FOR  LATITUDE  25° 

0  h. 

05" 

10" 

15" 

21" 

27" 

33" 

40" 

48" 

57" 

2 

08 

14 

19 

25 

31 

38 

46 

54 

1'05 

3 

12 

18 

24 

30 

37 

44 

53 

1'04 

1  18 

4 
5 

23 

49 

29 
59 

«5 
I'lO  • 

45 
1'24 

53 
1'52 

1'03 
207 

1'16 
244 

131 
346 

152 
543 

FOR  LATITUDE  27°  307 


0  h. 

08" 

13" 

18" 

24" 

30" 

36" 

44" 

52" 

1'02" 

?, 

11 

16 

22 

28 

34 

41 

49 

I'OO 

1  10 

3 

17 

22 

28 

35 

42 

50 

I'OO 

1  11 

1  26 

4 

28 

35 

42 

50 

i;00 

I'll 

126 

143 

209 

5 

54 

1'05 

1'18 

1'34 

154 

224 

311 

438 

8  15 

FOR  LATITUDE  30° 


0  h. 

10" 

15" 

21" 

27" 

33" 

40" 

48" 

57" 

1'08" 

2 

14 

19 

25 

31 

38 

46 

54 

1'05 

1  18 

3 

20 

26 

32 

39 

47 

55 

1'06 

1  19 

136 

4 

32 

39 

46 

52 

1'06 

1'19 

1  35 

1  57 

229 

5 

I'OO 

I'lO 

1'24 

1'52 

207 

244 

346 

543 

1306 

I 


OF  THE 
UNIVERSITY 

OF 


80 


REFRACTIONS  IN  DECLINATION 


0 

DECLINATIONS 

< 

FOR  LATITUDE  32°  30' 

o 
E 

+  20° 

+  15° 

-1-10° 

+5° 

0° 

—  5° 

—10° 

—15° 

—20° 

0  h. 

13" 

18" 

24" 

30" 

36" 

44" 

52* 

1'02" 

1'14" 

2 

17 

22 

28 

35 

42 

50 

I'OO 

1  11 

1  26 

3 
4 

23 
35 

29 
43 

35 
51 

43 
I'Ol 

,51 

I'Ol 
127 

1  13 
146 

128 
2  13 

147 
254 

5 

1'03 

1'15 

1/31 

153 

220 

305 

425 

736 

FOR  LATITUDE  35° 


0  h. 

15" 

21" 

27" 

33" 

40" 

48" 

57" 

1'08" 

1'  21" 

2 

20 

25 

32 

38 

46 

55 

1'05 

1  18 

1  35 

3 

26 

33 

39 

47 

56 

1'07 

121 

138 

200 

4 

39 

47 

56 

1'07 

1'20 

1  36 

1  59 

232 

3  25 

5 

1'07 

1'20 

1'38 

200 

234 

329 

5  14 

10  16 

FOR  LATITUDE  37°  30' 


0  h. 

18" 

24" 

30" 

36" 

44" 

52" 

1'02" 

1'14" 

1'29" 

2 

22 

28 

35 

42 

50 

I'OO 

1  12 

126 

1  45 

3 

29 

36 

43 

52 

1'02 

1  14 

1  29 

149 

2  16 

4 

43 

51 

I'Ol 

1'13 

127 

149 

2  14 

254 

405 

5 

I'll 

1'26 

154 

2  10 

249 

355 

6  15 

1458 

FOR  LATITUDE  40° 


0  h. 

21" 

27" 

33" 

40" 

48" 

57" 

1'08" 

1'21" 

1'39" 

2 

25 

32 

39 

46 

52 

1'06 

1  19 

1  35 

1  57 

3 

33 

40 

48 

57 

1'08 

121 

138 

202 

236 

4 

47 

55 

1'06 

1'19 

136 

158 

230 

321 

459 

5 

1'15 

1'31 

1  51 

• 

220 

305 

425 

734 

25  18 

FOR  LATITUDE  42°  30' 


0  h. 

24" 

30" 

36" 

44" 

52" 

1'02" 

1'  14" 

1'29" 

1'49" 

2 

28 

35 

39 

50 

I'OO 

1  12 

126 

145 

2  11 

3 

36 

.   43 

52 

1'02 

1  13 

1  29 

1  49 

2  17 

259 

4 

50 

I'OO 

I'll 

1  26 

144 

2  10 

249 

355 

616 

5 

1'19 

136 

158 

230 

322 

£00 

924 

FOR  LATITUDE  45° 


0  h. 

27" 

33" 

40" 

48" 

57" 

1'08" 

1'21" 

1'39" 

2'02" 

2 

32 

39 

46 

52 

1'06 

1  19 

135 

157 

229 

3 

40 

47 

56 

1'07 

1  21 

138 

200 

234 

329 

4 

54 

1'04 

1'16 

133 

154 

224 

3  11 

438 

815 

5 

1'23 

141 

205 

241 

340 

540 

1202 

FOR  LATITUDE  47°  307 


0  h. 

30" 

36" 

44" 

52" 

1'02" 

1'14" 

1'29" 

1'49" 

2'  18" 

2 

35 

42 

50 

I'OO 

1  12 

126 

1  45 

201 

251 

3 

43 

51 

I'Ol 

1  13 

128 

147 

2  15 

256 

408 

4 

56 

1'09 

1  23 

140 

205 

240 

339 

537 

11  18 

5 

1'27 

146 

2  12 

252 

401 

630 

16  19 

REFRACTIONS  IN  DECLINATION 


81 


HOUR  ANGL 

DECLINATIONS 

FOR  LATITUDE  50° 

+20° 

-(-15° 

+10° 

+5° 

0° 

—5° 

—10° 

—15° 

—20° 

0  h. 
2 
3 
4 
5 

33" 
38 
47 
1'02 
130 

40" 
46 
56 
1'14 
151 

48" 
55 
1'06 
129 
219 

57" 
1'06 
1  19 
148 
304 

1'08" 
1  18 
136 
216 
422 

1'21" 
135 
229 
258 
728 

1'39" 
1  57 
231 
418 
24  10 

2'02" 
228 
323 
659 

2'36" 
3  19 
502 
1947 

FOR  LATITUDE  52°  30' 


0  h. 

36" 

44" 

52" 

1'02" 

1'14" 

1'29" 

1'49" 

2'  18" 

3'05" 

2 

43 

50 

59 

1  11 

126 

142 

223 

249 

355 

3 

50 

I'OO 

I'll 

126 

145 

211 

251 

258 

622 

4 

1'05 

M8 

135 

2  10 

228 

3  19 

453 

842 

5 

134 

1  56 

227 

3  16 

447 

852 

FOR  LATITUDE  55° 


0  h, 

40" 

48" 

57" 

1'08" 

1'21" 

1'39" 

2'02" 

2'36" 

3'33" 

2 

46 

55 

1'05 

1  18 

134 

1  56 

230 

3  15 

447 

3 

55 

1'06 

1  19 

135 

158 

230 

321 

458 

919 

4 

no 

123 

142 

206 

243 

344 

549 

1241 

5 

137 

201 

234 

328 

5  15 

1018 

FOR  LATITUDE  57°  30' 


0  h. 

44" 

52" 

1'02" 

1'14" 

1'29" 

1'49" 

2'  18" 

3'05" 

4'37" 

2 

50 

59 

1  11 

125 

143 

209 

247 

351 

604 

3 

58 

I'lO 

124 

142 

207 

243 

345 

550 

1247 

4 

I'll 

125 

143 

2  10 

250 

355 

614 

1449 

5 

141 

206 

242 

342 

546 

1226 

FOR  LATITUDE  60° 


0  h. 

48" 

57" 

1'08" 

1'21" 

1'39" 

2'02" 

2'36" 

3'33" 

5'23" 

2 

54 

1'04 

1  17 

133 

1  54 

224 

3  12 

438 

8  15 

3 

1'03 

1  15 

130 

151 

220 

304 

424 

731 

2444 

4 

1  18 

134 

1  56 

228 

3  18 

450 

853 

5 

145 

211 

250 

357 

621 

1532 

FOR  LATITUDE  62°  30' 


0  h. 

52" 

1'02" 

1'14" 

1'29" 

1'50" 

2'  18" 

3'00" 

4'  17" 

7'  13" 

2 

58 

109 

123 

141 

206 

243 

344 

550 

1244 

3 

1'07 

123 

138 

201 

235 

330 

5  16 

1024 

4 

1  23 

1  40 

205 

240 

340 

537 

1150 

5 

1  48 

2  17 

259 

414 

703 

FOR  LATITUDE  65° 


0  h. 

57" 

1'08" 

1'21" 

1'39* 

2'02" 

2'36" 

3'33" 

5'23" 

10'51" 

2 

1'03 

1  16 

131 

152 

221 

307 

428 

744 

3 

1  12 

127 

146 

2  12 

252 

402 

633 

4 

1  27 

1  47 

2  13 

254 

405 

640 

5             152 

222 

308 

430 

752 

82 


REFRACTIONS  IN  DECLINATION 


HOUR  ANGL 

DECLINATIONS 

FOR  LATITUDE  67°  30' 

+20° 

+  15° 

+10° 

+  5° 

0° 

—5° 

—10° 

—15° 

—20° 

0  h. 
2 
3 
4 
5 

1'02" 
108 
1  17 
132 
156 

1'14" 
1  22 
134 
153 

228 

1'29" 
140 
155 
223 
3  17 

1'50" 
203 
226 
3  14 
440 

2'  18" 
239 
3  14 
435 
851 

3'00" 
337 
444 
805 

4'  17" 
532 
834 

T  13" 
1128 

FOR  LATITUDE  70° 


0  h. 

1'08" 

1'21» 

1'39" 

2'02" 

2'36" 

3'33" 

5'23" 

icxs!" 

2 

1  14 

129 

1  50 

2  18 

300 

4  17 

7  13 

3 

123 

143 

205 

241 

341 

559 

1215 

4 

137 

200 

234 

328 

520 

10  12 

5 

202 

233 

327 

511 

1005 

COMPUTING   DECLINATIONS  83 

TO   COMPUTE    THE  DECLINATION 

Suppose  the  corrected  declination  is  desired  for  the  dif- 
ferent hours  of  February  15,  1905,  at  Troy,  N.  Y.  The 
latitude  is  42°  44'.  The  longitude  is  practically  five  hours; 
so  that  the  declination  given  in  the  Ephemeris  for  apparent 
noon  of  that  day  at  Greenwich  would  be  that  for  7  A.  M.  at 
Troy,  or  five  hours  earlier.  Note  carefully  the  algebraic 
signs.  The  declination  is  South  or  minus.  Its  hourly  dif- 
ference is  plus.  The  refraction  always  is  plus.  Hence  we 
use  the  algebraic  sum,  thus :  — 

S  12°  47'  57".  5  is  the  tabular  declination  for  7  A.  M. 

51".  3  Sub.  hr.  dif. 


— 12°  47/    6".2  +    ref.     (4hrs.)    3'  21"  =  — 12°  43'  45",    8A.M. 
51".  3 


— 12°  46'  14".  9  +    ref.     (3hrs.)    2'  02"  =  — 12°  44' 13",    9A.M. 
51".  3 


—  12°  45'  23".6  +    ref.     (2  hrs.)     1'  35"  =  —12°  43'  49",  10  A.  M. 
51".  3 


—  12°  44'  32".  3   +     ref.     (1  hr.  )     1'  20"  =  —12°  43'  12",  11  A.  M. 
51".  3 


—  12°  43'  41".0  +    ref.     (0  hr.  )    1'  20"  =  —12°  42'  21",  12  M. 
51  ".3 


—  12°  42'  49".7  +    ref.     (1  hr.  )    1'  20"  =  —12°  41'  30",    1  P.  M. 
51".  3 


—  12°  41' 58".  4  +     ref.     (2  hrs.)     1' 35"  =  —12°  40' 23",    2P.M. 
51".  3 


— 12°  41' 07".  1  +    ref.     (3  hrs.)    2'  02"  =  — 12°  39'  05",    3P.M. 
51".  3 


— 12°  40' 15". 8  +    ref.     (4  hrs.)     3' 21"  =  —12°  36' 55",    4  P.  M. 


84  COMPUTING   DECLINATIONS 

Again,  suppose  the  corrected  declination  is  desired  for  the 
different  hours  of  May  15,  1905,  at  Troy.  Now  the  declina- 
tion is  North  or  plus  and  the  hourly  difference  is  plus. 

N  18°  46'  14".  9    +    ref.    (5  hrs.)    1' 24"    -    18°  47'  39",    7   A.M. 
35".  7  Addhr.  dif. 


18°  46'  50".  6    +     ref.    (4  hrs.)        54"    =    18°  47'  45",    8   A.M. 
35".  7 


18°47/26".3    +    ref.    (3  hrs.)        39"    =     18°  48'  05",    9   A.M. 
35".  7 


18°48'02".0    +    ref.    (2  hrs.)        30"    =     18°  48'  32",  10   A.  M. 
35".  7 


18°  48' 37".  7    +    ref.    (1     hr.)        26"    =     18°  49'  04",  11    A.M. 
'      35".  7 


18°  49' 13".  4     +     ref.    (0    hr.)         26"    =     18°  49'  39",  12   M. 
35".  7 


18°49'49".l     +    ref.    (1     hr.)        26"    =     18°  50'  15",     1    P.  M. 
35".  7 


18°  50' 24". 8    +    ref.    (2  hrs.)         30"    =     18°  50' 55",    2    P.  M. 
35".  7 


18°51'00".5    +    ref.    (3  hrs.)        39"    =     18°  5 1'  39",    3    P.M. 
35".  7 


18°51'36".2    +    ref.    (4  hrs.)        54"    =    18°  52'  30",    4    P.M. 
35".  7 


18°  52' 11". 9    +    ref.    (5  hrs.)     1' 24"   =    18°  53' 36",    5    P.   M. 

We  believe  it  will  be  found  that  the  use  of  the  table  as 
illustrated  above  will  not  only  relieve  the  surveyor  of  the  per- 
plexity hitherto  attending  the  subject  of  refractions,  but  will 
also  enable  him  to  secure  more  accurate  results  than  were 
possible  by  the  methods  usually  given. 


LATITUDE  .       85 

The  calculation  of  the  declination  for  the  different  hours 
of  the  day  should,  of  course,  be  made  and  noted  before  the 
surveyor  begins  his  work,  that  he  may  lay  off  the  change  from 
hour  to  hour,  from  a  table  prepared  as  before  described. 

TO  FIND    THE  LATITUDE 

Level  the  instrument  very  carefully,  using  the  level  of  the 
telescope,  until  the  bubble  will  remain  in  the  middle  during  a 
complete  revolution  of  the  instrument,  the  tangent  movement 
of  the  telescope  being  used  in  connection  with  the  leveling- 
screws,  and  the  axis  of  the  telescope  being  firmly  clamped. 

Clamp  the  vertical  arc,  so  that  its  zero  and  the  zero  of  its 
vernier  coincide  as  near  as  may  be,  and  bring  them  into  exact 
line  by  the  tangent  screw  of  the  vernier. 

Set  off  upon  the  proper  arc  the  declination  of  the  sun  for 
noon  of  the  given  day,  corrected  for  the  meridional  refrac- 
tion. Note  the  equation  of  time,  and  fifteen  or  twenty  min- 
utes before  noon  direct  the  telescope  to  the  north  and  lower 
the  objective  end  until  the  sun's  image  can  be  brought  nearly 
into  position  between  the  equatorial  lines,  by  moving  the 
instrument  upon  its  spindle  and  the  declination  arc  from  side 
to  side. 

The  declination  arc  being  brought  directly  in  line  with  the 
telescope,  clamp  the  axis,  and  with  the  tangent  screw  of  the 
telescope  axis  bring  the  image  precisely  between  the  lines, 
following  the  sun's  motion  as  the  image  runs  below  the  lower 
equatorial  line,  or,  in  other  words,  as  long  *as  the  sun  con- 
tinues to  rise  in  "the  heavens. 

When  the  sun  reaches  the  meridian  the  image  will  remain 
stationary  in  altitude  for  an  instant,  and  will  then  begin  to 
rise  on  the  plate. 

The  moment  the  image  ceases  to  run  below  is  apparent 


86  LATITUDE 

noon,  when  the  index  of  the  hour  arc  should  indicate  XII, 
and  the  latitude  be  determined  by  the  reading  of  the  vertical 
arc. 

The  angle  through  which  the  polar  axis  has  moved  in  the 
operation  just  described  is  measured  from  the  zenith  instead 
of  the  horizon,  as  in  the  Solar  Compass,  so  that  the  angle 
read  on  the  vertical  limb  is  the  complement  of  the  latitude. 

The  latitude  itself  is  readily  found  by  subtracting  this 
angle  from  90°.  Thus  at  Troy  the  reading  of  the  limb  being 
found  as  above  directed  to  be  47°  16',  the  latitude  will  be  90° 
—  47°  16'  =  42°  44'.  The  latitude  may  also  be  read  direct 
by  referring  to  the  inner  row  of  figures  on  the  arc,  beginning 
with  90  in  the  middle  and  reading  to  10  on  either  side. 

TIME  FOR  USING  THE  SOLAR 
While  the  solar  can  be  used  with  advantage  at  all  seasons 
of  the  year,  the  most  favorable  time  is  the  summer,  when  the 
declination  is  north  and  the  days  are  long  and  more  generally 
fair.  It  is  best  not  to  take  the  sun  at  morning  and  evening 
when  it  is  within  half  an  hour  of  the  horizon,  nor  at  noon  for 
about  the  same  interval  before  and  after  it  passes  the  meridian. 

ADVANTAGES  OF  THE  SOLAR  IN  SURVEYING 

While  the  solar  is  indispensable  in  the  survey  of  public 
lands,  it  also  possesses  important  advantages  over  the  mag- 
netic needle  compass  when  used  in  the  surveys  of  farms,  and 
similar  work.  Not  only  can  lines  be  run  and  angles  be  meas- 
ured without  regard  to  the  diurnal  variation  or  the  effect  of 
local  attraction,  but  the  bearings,  being  taken  from  the  true 
meridian,  will  remain  unchanged  for  all  time. 

In  favorable  weather  surveys  can  be  made  more  rapidly 
than  with  the  needle  instrument,  there  being  no  time 


ADVANTAGES   OF  THE  SOLAR  87 

consumed  in  waiting  for  the  needle  to  settle,  or  in  avoiding 
the  errors  due  to  local  attraction. 

When  the  sun  is  obscured  the  lines  can  be  run  by  the 
needle  alone,  it  being  always  kept  with  the  sun,  or  at  0  on  its 
arc,  thus  indicating  the  direction  of  the  true  meridian.  The 
sun,  however,  must  be  regarded  as  the  most  reliable  guide, 
and  should,  if  possible,  be  taken  at  every  station. 

With  a  transit  having  both  vertical  and  horizontal  limbs, 
direct  observations  may  be  taken  on  the  sun  to  find  the 

DIRECT  meridian.  The  best  time  is  about  three 

OBSERVATION  hours  before  or  after  noon.  A  colored  or 
smoked  glass  darkener  will  be  necessary  over  the  eyepiece 
to  protect  the  eye.  The  observations  to  be  taken  are  those 
of  the  altitude  of  the  sun  and  its  horizontal  angle  from  a  fixed 
point,  at  the  same  instant.  It  is  best  to  take  a  number  of 
these,  say  three  or  five,  so  as  to  check ;  and  if  the  telescope 
is  reversed  and  another  set  taken,  the  mean  of  the  two  sets 
will  eliminate  many  inaccuracies.  It  is  also  an  advantage  to 
use  the  lower  limb  of  the  sun  in  the  morning  and  the  upper 
limb  in  the  afternoon,  it  being  easier  to  judge  the  tangency 
of  image  and  cross-wires.  Allowance  is  then  made  for  the 
semi-diameter  of  the  sun,  which  varies  from  15^  to  16^ 
minutes.  It  will  be  sufficiently  close  to  have  the  vertical 
wire  bisect  the  sun,  but  the  altitude  must  be  taken  with 
care.  The  transit  must  be  accurately  leveled  and  adjusted. 

To  reduce  the  observations  there  are  many  forms,  all 
deduced  from  the  same  formula.  The  form  much  favored  is 

tan2  JA    _  sin  [S-(900-alt.)].sin  [S-(90o-lat.)] 
sin  S.  sin  [S— (90°—  dec.)] 

REDUCTION       In  which  "A"  is  the  azimuth  of  the  sun  or 
FORMULA        horizontal    distance    from   the   meridian,   and 
"S"  is  one -half  the  sum  of  (90° — alt.  corrected  for  refrac- 
tion) -f-  (90°— lat.)  +  (90°— dec.)      Note  the  sign  of  the 


88  DIRECT  OBSERVATION 

declination.      When  South  would  be  (90° —  (—dec. )  =  90° 
4-  dec. 

EXAMPLE:     Place,  Troy,  N.  Y.     Time  3h.  30m.  P.  M., 
March  31,  1906. 

The  horizontal  angle  from  a  fixed  point  to  sun's  center 241°  46' 

Observed  altitude  of  upper  limb  of  sun 30°  31'  10" 

Obs.  alt.  — refraction  1'  40" — semi-diameter  16'  =  alt.  of 

sun's  center 30°  13'  30" 

Declination  for  day"  and  hour 4°  30'  30" 

Latitude 42°  44' 

90°  —  alt.  =  59°  46'  30",  90°  —  dec.  =  85°  29'  30", 

90°  —  lat.  =  47°  16',  2  S  =  192°  32',  S  =    96°  16' 

log.  sin  [S— (90°— alt.)]  =  9.77430 

log.  sin  [S— (90°— lat.)]  =  9.87778 

9.65208 

log.  sin  S  =    9.99740 

log.  sin  [S— (90°  — dec.)]  =9.27173 
9.26913 

log.  tan2  }  A  =  0.38295 
log.  tan   \  A  =  0.19148 

\  A  =  57°  14'  25"  and  A  =  114°  28'  50"  West  of  North. 
If  in  the  morning  would  be  East  of  North. 
Apply  this  to  the  horizontal  angle  from  the  fixed  point  to 
the  sun  and  we  have  356°  14'  50",  which  is  the  reading  of 
the  horizontal   limb  when  the  telescope   is   pointed   North. 
Set  this  reading  off  on  the  limb  and  the  telescope  will  be  in 
the  plane  of  the  meridian. 

A  table  of  Mean  Refractions  due  to  altitude. 

Bar.  30  ins.,  Ther.  50°  F.,  always  minus. 

App.  alt.  Ref.         jApp.  alt.        Ref.         JApp.  alt.        Ref.         |App.  alt.        Ref. 


5° 

9'  46"    10° 

5'  16" 

20° 

2'  37" 

50° 

0'  48" 

6° 

8'  23" 

12° 

4'  25" 

25° 

2'  03" 

60° 

0'  33" 

7° 

7'  20" 

14° 

3'  47" 

30° 

1'  40" 

70° 

0'  21" 

8° 

6'  30" 

16° 

3'  19" 

35° 

1'  22" 

80° 

0'  10" 

9° 

6'  49" 

18° 

2'  56" 

40° 

1'  09" 

90° 

0'  0" 

DIRECT  OBSERVATION 


89 


A  Table  of  Semi -Diameters  of  the  Sun. 


Jan.  1,  16'  17" 
Feb.  1,  16'  14" 
Mar.  1,  16'  09" 


April  1,  If/  01" 
May  1,  15'  53" 
June  1,  15'  47" 


July  1,  15'  45" 
Aug.  1,  15'  47" 
Sept.  1,  15'  42" 


Oct.  1,  16'  00" 
Nov.  1,  16'  08" 
Dec.  1,  16'  14" 


NO.   192    SOLAR  SCREEN 
Price,  $5.00. 

If  desired,  we  furnish  a  solar  screen  arranged  to  clamp  to 
the  eyepiece  end  of  the  telescope,  and  detachable  at  will. 
On  this  screen  the  image  of  the  sun  and 
cross-wires  can  be  readily  -observed,  a 
greater  movement  of  the  eyepiece,  however,  being  required. 


SOLAR   SCREEN 


90  PATENT  LATITUDE  LEVEL 

PATENT  LATITUDE  LEVEL 

This  attachment,  shown  in  the  cut  on  page  37,  is  used  for 
recovering  the  latitude  on  a  solar  transit  without  referring  to 
the  vertical  arc,  and  also  for  setting  the  telescope  at  any 
desired  angle  in  running  grades  and  similar  work. 

It  consists  of  a  level  connected  by  a  short  conical  socket 
with  the  end  of  the  telescope  axis,  to  which  it  is  clamped  by  a 
milled-head  screw,  and  made  adjustable  by  a  tangent  screw 
and  spring  on  the  enlarged  end  of  the  tube.  When  the  clamp 
screw  is  released  the  level  turns  vertically  upon  the  axis,  and 
can  thus  be  set  at  any  angle  with  the  telescope,  the  final 
adjustment  being  made  by  the  tangent  screw. 

.  The  latitude  being  set  off  upon  the  vertical  arc  as  usual, 
the  level  is  clamped  and  brought  into  the  middle,  as  above 
described. 

The  telescope  may  then  be  released  and  used  in  running 
lines,  until  it  is  desired  to  recover  the  latitude  again.  This  is 
easily  and  accurately  done  without  referring  to  the  vertical 
arc.  The  use  of  the  attachment  in  running  any  desired  grade 
is  readily  understood. 

We  furnish  this  attachment  without  extra  charge  with  any 
new  solar  instrument. 

Price  of  Patent  Latitude  Level  added  to  an  old  Transit,  $6.00 


JONES  LATITUDE  ARC 


91 

UNIVEi 


JONES  LATITUDE  ARC 

When  this  attachment  is  used  the  vertical  arc  is  omitted, 
and  is  replaced  by  a  double  latitude  arc  attached  to  the  under 
side  of  the  telescope,  as  shown.  The  smaller  arc,  having  its 
center  directly  under  the  cross-bar  of  the  telescope,  has  an 
arm  with  vernier  reading  the  arc  to  single  minutes,  and 
carries  also  a  level-tube  open  at  both  top  and  bottom,  with  a 
scale  over  each  opening. 

In  obtaining  latitudes  with  this  attachment,  the  declination 
being  set  off  as  usual,  the  level-bubble  should  be  brought  into 
the  middle  of  its  scale  when  the  sun  is  on  the  meridian. 

The  reading  of  the  smaller  arc  then  gives  the  latitude  of 
the  place,  and  in  all  further  observations  of  the  latitude  refer- 
ence is  made  to  the  level  rather  than  to  the  graduations,  the 
level  being  easily  brought  into  the  middle  of  the  scale.  This 


92  JONES  LATITUDE  ARC 

enables  the  surveyor  to  recover  the  latitude  more  rapidly  than 
with  the  ordinary  vertical  arc. 

Minute  changes,  as  long  lines  are  run  either  north  or 
south,  may  be  computed  and  set  off  on  the  larger  arc,  which 
reads  by  its  vernier  to  ten  seconds. 

But  one  test  of  the  adjustment  of  this  attachment  is  re- 
quired, that  both  arcs  should  read  zero  when  the  telescope  is 
made  horizontal  by  its  long  level,  and  the  smaller  level  of  the 
arc  below  is  also  brought  to  the  middle  of  its  scale. 

If  not  correct,  they  may  be  adjusted  by  loosening  the 
screws  which  fasten  each  arc,  and  moving  the  arcs  until  the 
zeros  of  both  are  in  coincidence  with  the  zeros  of  their 
verniers,  care  being  taken  to  set  the  screws  firmly  again. 

PRICES 

JONES  Latitude  Arc,  with  reversible  level-bubble $73.00 

When  furnished  with  a  new  Transit  of  our  make  in  place  of  the 
ordinary  vertical  arc,  the  JONES  Latitude  Arc,  with  reversible 

level-bubble,  increases  the  cost  of  the  instrument 55.00 

Thus  :     The  Light  Mountain  Transit,  with  Solar  Attachment  and 

JONES  Latitude  Arc,  costs 300.00 


ADJUSTMENTS  OF  THE  SOLAR  93 

TO  ADJUST    THE  SOLAR  ATTACHMENT 

To  adjust  the  solar  attachment,  proceed  as  follows : 
SOLAR  LENSES      Detach  the  declination  arm  by  taking  off 
AND  LINES          the  clamp  and  tangent  screws,  and  remov- 
ing the  center  by  which  the  arm  is  pivoted  on  the  arc. 

Substitute  for  the  declination  arm  upon  the  attachment  the 
adjusting-bar  furnished  with  every  solar  instrument,  the  center 
of  the  declination  arm  fitting  into  the  hole  at  one  end  of  the 
bar,  and  the  bar  being  further  secured  to  the  attachment  by 
the  clamp  screw  passing  through  the  hole  in  the  declination 
arc  left  by  the  removal  of  the  tangent  screw,  into  the  threaded 
hole  at  the  other  end  of  the  adjusting-bar,  thus  forming  a 
support  upon  which  the  declination  arm  can  be  adjusted. 

Place  the  declination  arm  on  the  adjuster,  turn  one  end  to 
the  sun,  and  bring  it  into  such  a  position  that  the  image  of 
the  sun  is  made  to  appear  precisely  between  the  equatorial 
lines  on  the  opposite  plate. 

Carefully  turn  the  arm  over,  until  it  rests  upon  the  adjuster 
by  the  opposite  faces  of  the  rectangular  blocks,  and  again 
observe  the  sun's  image.  If  it  remains  between  the  lines  as 
before,  the  arm  is  in  adjustment.  If  not,  loosen  the  three 
small  screws  and  move  the  silver  plate  under  their  heads  until 
one-half  the  error  in  the  position  of  the  sun's  image  is 
removed. 

Bring  the  image  again  between  the  lines,  and  repeat  the 
operation  as  above  on  both  ends  of  the  arm,  until  the  image 
will  remain  between  the  lines  of  the  plate  in  both  positions 
of  the  arm,  when  it  will  be  in  proper  adjustment,  and  the  arm 
may  be  replaced  in  its  former  position  on  the  attachment. 
This  adjustment  is  very  rarely  needed  in  our  instruments,  the 
lenses  being  cemented  in  their  cells  and  the  plates  securely 
fastened. 


94  ADJUSTMENTS   OF   THE   SOLAR 

To  adjust  the  vernier  of  the  declination  arc:  Set  the 
DECLINATION  vernier-  at  zero,  and  raise  or  lower  the  tele- 
ARC  scope  until  the  sun's  image  appears  exactly 

between  the  equatorial  lines. 

Having  the  telescope  axis  clamped,  carefully  revolve  the 
arm  until  the  image  appears  on  the  other  plate.  If  precisely 
between  the  lines,  the  adjustment  is  complete.  If  not,  move 
the  declination  arm  by  its  tangent  screw  until  the  image  will 
come  precisely  between  the  lines  on  the  two  opposite  plates. 
Clamp  the  arm  and  remove  the  index  error  by  loosening  two 
screws  that  fasten  the  vernier ;  place  the  zeros  of  the  vernier 
and  limb  in  exact  coincidence,  tighten  the  screws,  and  the 
adjustment  is  complete. 

To  adjust  the  polar  axis :  Level  the  instrument  carefully 
by  the  long  level  of  the  telescope,  using  the  tangent  move- 
ment of  the  telescope  axis  in  connection  with 

POLAR   AXIS  .         .. 

.the  levelmg-screws,  until  the  bubble  will  re- 
main in  the  middle  during  a  complete  revolution  of  the 
instrument  upon  its  axis. 

Place  the  solar  attachment  upon  the  axis  and  see  that  it 
moves  easily  around  it.  Bring  the  declination  arm  into  the 
same  vertical  plane  with  the  telescope,  place  the  adjusting- 
level,  No.  196  (see  page  95),  upon  the  top  of  the  rec- 
tangular blocks,  and  bring  the  bubble  of  the  level  into  the 
middle  by  the  tangent  screw  of  the  declination  arc. 

Turn  the  arc  half-way  around,  bringing  it  again  parallel 
with  the  telescope,  and  note  the  position  of  the  level.  If  in 
the  middle,  the  polar  axis  is  vertical  in  that  direction.  If  not 
in  the  middle,  correct  one-half  the  error  by  the  capstan - 
head  adjusting-screws  under  the  base  of  the  polar  axis,  moving 
each  screw  of  the  pair  the  same  amount,  but  in  an  opposite 
direction.  Bring  the  level  to  the  middle  again  by  the  tangent 


ADJUSTMENTS   OF   THE   SOLAR  95 

screw  of  the  declination  arc,  and  repeat  the  operation  as 
before,  until  the  bubble  will  remain  in  the  middle  when  the 
adjusting-level  is  reversed. 

Pursue  the  same  course  in  adjusting  the  arc  in  the  second 
position,  or  over  the  telescope  axis,  and  when  completed  the 


NO.   196 

STRIDING  OR  ADJUSTING-LEVEL 

level  will  remain  in  the  middle  during  an  entire  revolution  of 
the  arc,  showing  that  the  polar  axis  is  at  right  angles  with  the 
level  under  the  telescope,  or  truly  vertical. 

As  this  is  by  far  the  most  delicate  and  important  adjust- 
ment of  the  solar  attachment,  it  should  be  made  with  the 
greatest  care,  the  bubble  being  kept  precisely  in  the  iriiddle 
and  frequently  inspected  in  the  course  of  the  adjustment. 

The  adjusting-level  is  supposed  to  be  itself  in  adjustment ; 
but  if  not,  it  can  be  easily  corrected  by  the  screw  shown  at 
one  end,  when  reversed'  upon  a  plane  surface,  exactly  as  a 
mason's  level  is  adjusted. 

To  adjust  the  hour  arc :  Whenever  the  instrument  is 
set  in  the  meridian,  as  will  be  hereafter 

HOUR  ARC          ,  «...'«  f        i 

described,  the  index  of  the  hour  arc  should 
read  apparent  time.  If  not,  loosen  the  two  flat-head  screws 
on  the  top  of  the  hour  circle,  and  with  the '  hand  turn  the 
circle  around  until  the  proper  reading  is  indicated,  fasten  the 
screws  again,  and  the  adjustment  will  be  complete. 


ASTRONOMICAL  TERMS 


TN  the  following  pages  we  define  the  terms  employed  in  the 
•*•  use  and  adjustment  of  the  solar  attachment,  which  may 
be  helpful  to  one  not  familiar  with  solar  instruments. 

The  sun  is  the  fixed  center  of  the  solar  system, 
although  for  convenience  it  is  often  spoken  of  as  in 
motion  around  the  earth. 

The  earth  makes  a  complete  revolution  around  the  sun  in 
three  hundred  and  sixty -five  days,  five  hours,  forty-eight  min- 
utes, and  forty-six  seconds.     It  also  rotates  about 

EARTH  ..  .  ,  ,     . 

an  imaginary  line  passing  through  its  center,  and 
termed  its  axis,  once  in  twenty-three  hours,  fifty-six  minutes, 
and  four  seconds,  mean  time,  turning  from  west  to  east. 

The  poles  are  the  extremities  of  the  axis.     That  in  our 

hemisphere,  known  as  the  north  pole,  if  produced  indefinitely 

toward  the  concave  surface  of  the  heavens,  would 

reach  a  point  near  the  polar  star,  called  the  north 

pole  of  the  heavens. 

The  equator  is  an  imaginary  line  passing  around  the  earth, 

equi -distant  from  the  poles,  and  in  a  plane  at  right  angles 

with  the  axis.     If  the  plane  of  the  equator  were 

produced  to  the  heavens,  it  would  form  what  is 

called  the  celestial  equator. 

The  orbit  of  the  earth  is  the  path  in  which  it 
moves  in  its  yearly  revolution.     If  the  plane  of  this 
orbit  were  produced  to  the  heavens,  it  would  form  the  eclip- 
tic, or  the  sun's  apparent  path  in  the  heavens. 

The  earth's  axis   is  inclined   to  its  orbit  at  an  angle  of 
about  23°  27',  making  an  angle  of  the  same  degree  between 

97 


98  ASTRONOMICAL    TERMS 

the  earth's   orbit    and  its  equator,   or  between    the    celestial 
equator  and  the  ecliptic. 

The  equinoxes  are  the  two  points  at  which 

EQUINOXES  ..      .  .   . 

the  ecliptic  and  the  celestial  equator  intersect 
one  another. 

The  declination  of  the  sun  is  its  angular  distance  north 
or  south  of  the  celestial  equator.  When  the  sun  is  at  the 
DECLINATION  equinoxes,  about  the  21st  of  March  and  the 
OF  THE  SUN  21st  of  September  of  each  year,  its  declina- 
tion is  0,  or  it  is  said  to  be  on  the  equator.  From  these 
points  its  declination  gradually  increases,  until  on  the  21st  of 
June  and  the  21st  of  December  it  is  23°  27'  distant  from  the 
equator. 

It  is  the  declination  which  causes  the  sun  to  appear  so 
much  higher  in  summer  than  in  winter,  its  altitude  in  the 
heavens  being  about  46°  54'  more  on  the  21st  of  June  than 
it  is  on  the  21st  of  December. 

The    horizon    of  a    place    is    the    visible   boundary  of   a 

plane,  tangent  to  the  earth  at  that  place,  or  at  right  angles 

to   a   vertical    line.       The    horizon,    or   a    hori- 

HORIZON  ,  , 

zontal  surface,  is  determined  by  the  surface 
of  a  liquid  at  rest,  or  by  the  spirit-levels  of  an  instru- 
ment. 

The  zenith    of    a  place    is  the    point    directly 
overhead,    in    a    line    at    right    angles   with    the 
horizon. 

The   meridian    circle    of    a  place  is  a  great 

MERIDIAN  ...  . 

circle  passing  through  the  zenith  of  that  place 
and  the  poles  of  the  earth. 

The  meridian,  or  true  north  and  south  line,  is  the  line 
determined  by  the  intersection  of  the  plane  of  the  meridian 
circle  with  the  plane  of  the  horizon. 


ASTRONOMICAL    TERMS  99 

The  meridian  altitude  of  the  sun  is 

MERIDIAN   ALTITUDE 

its  angular  elevation  above  the  hori- 
zon, when  passing  the  meridian  of  the  place. 

The  latitude  of  a  place  is  its  angular  distance 

LATITUDE  r     . 

north  or  south  of  the  equator,  measured  on  the 
meridian.  At  the  equator  the  latitude  is  0°,  and  at  the 
poles  90°. 

The"  longitude  of  a  place  is  its  angular  distance  east  or 
west  of  a  given   place   taken   as  the  starting  - 

LONGITUDE  &  ...  .  . 

point,  or  first  meridian.     It  is  measured  on  the 
equator  or  on  any  parallel  of  latitude. 

In  the  Nautical  Almanac,  which  is  commonly  used  with  a 
solar  instrument,  the  longitude  of  the  principal  places  in  the 
United  States  is  reckoned  from  Greenwich,  England,  and 
expressed  both  in  degrees  and  hours. 

The  zenith  distance  of  any  heavenly 

ZENITH    DISTANCE        ,       ,        .       .  ,. 

body  is  its  angular  distance  north  or 
south  of  the  zenith  of  a  place,  measured  when  the  body  is  on 
the  meridian. 

Suppose  a  person  to  be  on  the  equator  at  the  time  of  an 
equinox;  the  sun,  when  on  the  meridian,  would  be  in  the 
zenith  of  the  place,  and  the  poles  of  the  earth  would  lie  in 
the  plane  of  its  horizon. 

Disregarding,  for  the  present,  the  declination  of  the  sun, 
let  us  suppose  that  the  person  travels  toward  the  north 
pole.  As  he  passes  to  the  north,  the  sun  will  descend 
from  the  zenith,  and  the  pole  will  rise  from  the  horizon 
in  the  same  proportion,  until  when  he  arrives  at  the 
north  pole  of  the  earth  the  sun  will  have  declined  to  the 
horizon,  and  the  pole  of  the  heavens  will  have  reached  the 
zenith. 

The  altitude  of  the  pole  at  any  place,  or  the  distance  of 


100  ASTRONOMICAL    TERMS 

the  sun  from  the  zenith,  would,  in  the  case  supposed,  give 
the  observer  the  latitude  of  that  place. 

If  we  now  take  into  account  the  sun's  declination,  it  will 
increase  or  diminish  its  meridian  altitude,  according  as  it 
passes  north  or  south  of  the  equator ;  but  the  declination  of 
the  sun  at  any  time  being  known,  its  zenith  distance,  and 
therefore  the  latitude  of  the  place,  can  be  readily  ascertained 
by  an  observation  made  when  the  sun  is  on  the  meridian.  It 
is  by  this  method  that  we  obtain  the  latitude  of  any  place  by 
the  Solar  Compass. 

A  solar  day  is  the  interval  of  time  between  the  departure 
of  the  sun  from  the  meridian  of  a  place  and  its  suc- 

TIME 

ceeding  return  to  the  same  position.  The  length  of 
the  solar  day,  by  reason  of  the  inclination  of  the  earth's  axis, 
is  constantly  changing. 

In  order  to  have  a  uniform    measure  of   time,   we  have 

MEAN  recourse  to  what  is  termed  a  mean  solar  day, 

SOLAR  DAY  the  length  of  which  is  equal  to  the  mean  or 
average  of  all  the  solar  days  in  a  year. 

The  time  thus  given  is  called  mean  solar  time,   and  is 

MEAN  tne  same  at  any  instant  for  all  points  on  the 

SOLAR  TIME  same  meridian,  differing,  however,  at  points 
on  different  meridians. 

Since  November,  1883,  in  the  United  States,  the  mean 
solar  times  of  the  meridians  60°,  75°,  90°,  105°,  and  120° 
STANDARD  west  °f  Greenwich  are  adopted  as  standard 

TIME  time,  and  are  called  respectively  Colonial, 

Eastern,  Central,  Mountain,  and  Pacific  time.  The  time  of 
each  place  differs  from  that  of  the  next  by  one  hour.  Instead 
of  employing  the  local  mean  solar  time,  the  time  used  is  the 
mean  solar  time  at  the  nearest  of  the  standard  meridians. 

At  Troy,  N.  Y.,  the  longitude  is  73°  40'  west,   or   four 


ASTRONOMICAL    TERMS  101 

hours,  fifty -four  minutes  and  forty  seconds  ;  hence  the  mean 
solar  time  is  five  minutes  and  twenty  seconds  more  than  the 
standard  time.  At  Minneapolis  the  longitude  is  six  hours, 
twelve  minutes  and  fifty -seven  seconds ;  hence  the  mean 
solar  time  is  twelve  minutes  and  fifty-seven  seconds  less 
than  standard  time,  since  the  city  is  west  of  the  meridian. 
EQUATION  The  sun  is  sometimes  faster  and  sometimes 

OF  TIME         slower   than    the    clock,   the    difference    being 
called  the  equation  of  time. 

The  moment  when  the  sun  is  on    the   meridian  of    any 

place  is  called  apparent  noon,  and  this  being  ascertained,  we 

can,  by  adding  the  equation  of  time  for 

APPARENT    NOON  .  .  .          .     f 

the  given  day  to,  or  subtracting  it  from, 

apparent  noon,  according  as  the  sun  is  slow  or  fast,  obtain 
the  time  of  mean  noon,  which,  converted  to  standard  time,  is 
used  to  set  the  watch. 

As  the  earth  makes  a  complete  rotation  upon  its  axis  once 
a  day,  every  point  on  its  surface  must  pass  through  three 
DIFFERENCE  hundred  and  sixty  degrees  in  twenty-four 
OF  LONGITUDE  hours,  or  fifteen  degrees  in  one  hour,  and 
so  on  in  the  same  ratio.  As  the  rotation  is  from  west  to  east, 
the  sun  would  come  to  the  meridian  of  every  place  fifteen 
degrees  west  of  Greenwich  just  one  hour  later  than  the  time 
given  in  the  Ephemeris  for  apparent  noon  at  Greenwich. 

To  an  observer  at  Troy,  N.  Y.,  the  longitude  of  which  is, 
in  time,  four  hours,  fifty -four  minutes,  forty  seconds,  the  sun 
would  come  to  the  meridian  nearly  five  hours  later  than  at 
Greenwich,  and  thus,  when  it  was  12  M.  at  that  place  it 
would  be  only  about  7  A.  M.  in  Troy. 

By  reason  of  the  atmosphere,  the  rays  of 

REFRACTION  J 

light  from  the  sun  are  bent  out  of  their  course, 
as  to  make  its  altitude  appear  greater  than  is  actually  the  case. 


102  ASTRONOMICAL    TERMS 

The  refraction  varies  according  to  the  altitude  of  the  body 
observed,  being  zero  when  it  is  in  the  zenith,  about  one 
minute  when  midway  from  the  zenith  to  the  horizon,  and 
almost  thirty-four  minutes  when  in  the  horizon.  The  proper 
allowance  to  be  made  for  refraction  in  setting  off  the  declina- 
tion is  fully  explained  on  pages  77  to  84. 

If  the  latitude  and  declination  of  the  sun  were  both  zero, 
the  position  of  the  sun  at  noon  would  be  at  the  zenith  and 
EFFECT  QF  there  would  be  no  refraction.  At  any  other 
REFRACTION  latitude,  declination  or  hour,  the  apparent 
position  of  the  sun  would  be  lower  and  refraction  must  be 
taken  into  account.  As  refraction  is  due  to  altitude,  it  might 
be  suggested  to  lay  it  off  directly  on  the  vertical  limb ;  but  as 
this  would  alter  the  inclination  of  the  polar  axis,  it  must  be 
laid  off  on  the  declination  arc,  and  modified  to  suit  the 
proper  inclination  of  the  arc  due  to  latitude,  declination,  and 
hour  angle. 

Again,  the  angles  which  the  equatorial  lines  make  with 
the  horizon  are  continually  changing,  as  the  declination  arm 
is  made  to  follow  the  course  of  the  sun  during  an  entire  day. 
Thus  in  the  morning  and  evening  the  equatorial  lines  are 
more  or  less  inclined  to  the  horizon,  while  at  noon  they  are 
parallel  with  it.  It  follows  that  the  excess  of  refraction  at 
morning  and  evening  is  in  some  measure  balanced  by  the 
fact  that  the  position  of  the  sun's  image  with  reference  to  the 
equatorial  lines  is  then  less  affected  by  it,  on  account  of  the 
greater  inclination  of  the  lines  to  the  horizon. 


SURVEYORS'  COMPASSES 


SOLAR  COMPASS 
RAILROAD  COMPASS 
VERNIER  COMPASS 
PLAIN  COMPASS 


ATTACHMENTS  FOR  COMPASSES 

COMPOUND  BALL-SPINDLE 
LEVELING-ADOPTER 
LEVELING-HEAD 
TELESCOPIC  SIGHT 


SOLAR  COMPASS 


instrument  was  invented  by  William  A.  Burt,  of 
Michigan,  and  patented  by  him  in  1836.  It  came  into 
general  use  in  the  surveys  of  the  United  States  public  lands, 
the  principal  lines  of  which  are  required  to  be  run  with  refer- 
ence to  the  true  meridian. 

The  invention  long  since  became  public  property,  and  for 
nearly  sixty  years  the  Solar  Compass  has  been  manufactured 
by  us,  with  improvements  of  our  own  in  construction  in 
design  which  have  made  it  increasingly  popular  and  efficient. 

The  arrangement  of  the  sockets  and  plates  is  similar  to 
that  of  the  Surveyors'  Transit,  as  shown  on  page  40,  except 
that  the  sight  vanes  are  attached  to  the  under  plate  or  limb, 
and  this  revolves  around  the  upper  or  vernier  plate  on  which 
the  solar  parts  are  placed. 

The  limb  is  graduated  to  half-degrees,  is  figured  in  two 
rows,  0  to  360  and  0  to  90  each  way,  and  reads  by  two 
opposite  double  verniers  to  single  minutes.  The  graduations 
of  the  limb  and  all  other  arcs  of  the  Solar  Compass  are  made 
upon  silver. 

This  instrument  should  always  be  used  on  a  tripod,  with 

screws  for  ready  and  accurate  leveling,  and  a  tangent  screw 

for  directing   it   to   any   desired    point.      For   this 

purpose  a  leveling -head  with  tangent  screw,  similar 

to  that  shown  in  the  cut  of  the  Surveyors'  Transit,  is  furnished 

with  every  instrument. 

The    Solar    Compass    with    leveling-head,    but 

WEIGHT 

without  tripod,  weighs  about  fifteen  pounds. 
106 


SOLAR   COMPASS 


107 


NO.  210 

Price  as  shown,  including  leveling-screws  and  clamp  and  tangent  to  spindle 
and  with  tripod,  $210.00. 


108  SOLAR   COMPASS 

THE  SOLAR  APPARATUS 

The  solar  apparatus  is  seen  in  the  place  of  the  needle,  and 
operates  as  its  substitute  in  the  field.  It  consists  mainly  of 
three  arcs,  by  which  can  be  set  off  the  latitude  of  a  place,  the 
declination  of  the  sun,  and  the  hour  of  the  day. 

TO  ADJUST   THE  SOLAR   COMPASS 

The  adjustments  of  this  instrument  with  which  the  sur- 
veyor should  be  familiar  are  few  and  simple,  and  will  be 
mentioned  in  order. 

To  adjust  the  levels :  Proceed  as  directed  in  the  descrip- 
tion of  other  instruments,  by  bringing  the  bubbles  into  the 
middle  of  the  tubes  by  the  leveling-screws,  and  then  reversing 
the  instrument  upon  its  spindle  and  raising  or  lowering  the 
ends  of  the  tubes,  until  the  bubbles  will  remain  in  the  middle 
during  a  complete  revolution  of  the  instrument. 

-To  adjust  the  equatorial  lines  and  solar  lenses :  Same  as 
page  93. 

To  adjust  the  vernier  of  the  declination  arc:  Same  as 
page  94. 

To  adjust  the  solar  apparatus  to  the  compass  sights :  First 
level  the  instrument,  and  with  the  clamp  and  tangent  screws  set 
the  main  plate  at  ninety  degrees  by  the  verniers  and  horizon- 
tal limb.  Remove  the  clamp  and  tangent  screws  of  the  lati- 
tude arc,  and  raise  the  arc  until  the  polar  axis  is  by  estimation 
very  nearly  horizontal,  and,  if  necessary,  tighten  the  screws 
on  the  pivots  of  the  arc,  so  as  to  hold  it  in  this  position. 

Fix  the  vernier  of  the  declination  arc  at  zero,  and  direct 
the  outside  edges  of  the  lens  blocks  to  some  distant  and  well- 
marked  object,  and  observe  the  same  through  the  compass 
sights.  If  the  same  object  is  seen  by  both  observations,  and 


SOLAR   COMPASS  109 

the  verniers  read  to  ninety  degrees  on  the  limb,  the  adjust- 
ment is  complete.  If  not,  the  correction  must  be  made  by 
moving  the  compass  sights  or  changing  the  position  of  the 
verniers. 

As  the  solar  parts  are  attached  permanently  to  the  sockets, 
and  this  adjustment  is  made  by  the  manufacturer,  it  will  need 
no  attention  at  the  hands  of  the  surveyor,  except  in  case  of 
serious  accident.  The  other  adjustments  are  also  made  in  the 
process  of  finishing  the  instrument,  and  are  not  liable  to 
derangement  in  careful  use. 

TO  RUN  LINES    WITH   THE  SOLAR   COMPASS 

Having  set  off  the  latitude  and  declination  upon  their 
respective  arcs  and  the  instrument  being  in  adjustment,  the 
surveyor  is  ready  to  run  lines  by  the  sun. 

To  do  this,  the  instrument  is  set  over  the  station  and 
carefully  leveled,  the  plates  clamped  at  zero  on  the  horizontal 
limb,  and  the  sights  directed  north  and  south,  the  direction 
being  approximated  when  unknown  by  the  needle. 

The  solar  lens  is  then  turned  to  the  sun,  and,  with  one 
hand  on  the  instrument  and  the  other  on  the  revolving  arm, 
TRUE  both  are  moved  from  side  to  side,  until  the 
MERIDIAN  sun's  image  appears  on  the  silver  plate,  precisely 
between  the  equatorial  lines.  The  line  of  sight  will  then 
indicate  the  true  meridian,  and  the  observation  may  be  made 
and  the  flagman  put  in  position. 

When  a  due  east  and  west  line  is  to  be  run,  the  verniers 
of  the  horizontal  limb  are  set  at  ninety  degrees,  and  the  sim's 
image  kept  between  the  lines,  as  before. 

The  Solar  Compass  being  so  constructed  that  when  the 
sun's  image  is  in  position  the  limb  must  be  clamped  at  zero 
in  order  to  run  a  true  meridian  line,  it  will  be  evident  that 


110  SOLAR    COMPASS 

the  bearing  of  any  line  from  the  meridian  may  be  read  by  the 
verniers  of  the  limb  precisely  as  in  the  transit. 

In  running  lines,  the  magnetic  needle  may  be  kept  with 
the  sun,  that  is,  the  point  of  the  needle  is  made  to  indicate 
USE  OF  THE  zero  on  tne  arc  of  the  compass  box,  by 
NEEDLE  turning  the  tangent  screw  connected  with  its 
arm  on  the  opposite  side  of  the  plate.  Lines  can  thus  be  run 
by  the  needle  alone  in  case  of  the  temporary  disappearance  of 
the  sun,  but  the  surveyor  must  be  sure  that  there  is  no  local 
attraction.  The  magnetic  declination,  which  should  be  noted 
at  every  station,  is  read  off  on  the  arc  by  the  vernier  on  the 
arm  of  the  needle  box. 

In   using    the    Solar    Compass,   if   the  revolving  arm  be 

turned  a  little  to  one  side  of  its  proper  position,  a  false  or 

reflected  image  of  the  sun  will  appear  on  the 

FALSE   IMAGE          .. 

silver  plate  in  nearly  the  same  place  as  that 
occupied  by  the  true  one.  It  is  caused  by  the  reflection  of 
the  true  image  from  the  surface  of  the  arm,  and  is  a  fruitful 
source  of  error  to  the  inexperienced  surveyor.  It  can,  how- 
ever, be  readily  distinguished  from  the  real  image  by  being 
less  bright,  and  not  so  clearly  defined. 

When  the  bearings  of  lines,  such  as  the  course  of  a  stream 
or  the  boundaries  of  a  forest,  are  not  desired  with  the  cer- 
APPROXIMATE  tainty  given  by  the  verniers  and  the  hori- 
BEARINGS  zontal  limb,  a  rough  approximation  of  the 
angles  which  they  make  with  the  true  meridian  is  obtained  by 
the  graduations  on  the  outside  of  the  circular  plate.  In  this 
operation,  a  pencil  or  thin  straight-edge  of  any  kind  is  held 
perpendicularly  against  the  circular  edge  of  the  plate,  and 
moved  until  it  is  in  range  with  the  eye,  the  brass  center-pin, 
and  the  object  observed.  The  bearing  of  the  line  is  then 
read  off  at  the  point  where  the  pencil  is  placed. 


SOLAR   COMPASS  v     111 

SUPERIORITY  OF  OUR   SOLAR   COMPASSES 
The   Solar  Compass  as  first  made,   though  planned  with 

great    ingenuity  in   its   general   arrangement,   was  extremely 

rude  in  its  mechanical  details  and  adjustments. 

The  points  in  which  we  claim  the  superiority  of  our  Solar 

Compass  over  any  other  manufactured  are  partially  shown  in 

the  cut  on  page  107,  and  may  be  stated  in  detail  as  follows : 

1.  A  motion  of  the  horizontal  plates  entirely  free  from  friction,  com- 
bined with  perfect  rigidity. 

2.  A  tangent  movement  to  the  limb,  as  shown  under  the  plate, 
o.     A  tangent  movement  with  clamp  to  the  declination  arc. 

4.     A  tangent  movement  with  clamp  to  the  latitude  arc. 
f>.     A  tangent  movement  for  the  whole  instrument  about  its  socket. 
6.      Increased  facility  of  adjustment,  and  therefore  an  important  saving 
of  time. 


RAILROAD    COMPASS 


'"F*  HE  Railroad  Compass  is  an  instrument  intended  for  land 
surveying  in  localities  where  it  is  necessary  to  measure 
horizontal  angles  independently  of   the  needle,  as  incases  of 
local  attraction. 

The  accuracy  and  minuteness  of  the  horizontal  angles 
indicated  by  this  instrument,  together  with  its  perfect  adapta- 
tion to  all  the  purposes  for  which  the  Vernier  Compass  can 
be  used,  have  brought  it  into  use  in  many  localities  where 
land  is  so  valuable  as  to  require  more  careful  surveys  than  are 
practicable  with  a  needle  instrument. 

This  instrument  is  a  compass  of  the  highest  grade,  with  a 

graduated   limb  and  verniers  like  those  of   the  transit.     As 

shown    on    page  114,  it  has  the    main 

PLATES  AND   LIMB 

plate,  levels,  sights,  and  needle  of  the 

ordinary  compass,  and,  in  addition,  underneath  the  main 
plate,  a  graduated  circle  or  limb  by  which  horizontal  angles 
to  single  minutes  can  be  taken  independently  of  the  needle. 
The  limb  is  figured  in  two  rows,  0  to  360  and  0  to  90 
each  way. 

The  arrangement  of  the  sockets  is  like  that  of  the  Survey- 
ors' Transit  with  two  verniers  to  limb,  and  the 

SOCKETS  ,  ,          ,     .        ,, 

plates  can   be  separated   and   replaced   in    the 
same  manner. 

The  verniers  are  attached  to  the  under  surface  of  the  main 
•  plate  at  an  angle  of  thirty  degrees  with  the  line 

VERNIERS  .       .    ,  .  ,      . 

of   sights,   the  vernier  openings  being  covered 
with  glass  to  protect  the  graduations  from  dust  and  moisture. 
The  connection   between   the   two  plates  is  made   by  a 
112 


RAILROAD   COMPASS  113 

clamp  and  tangent  movement  with  opposing  spring,  shown 
at  /  underneath  the  plates. 

The  needle-lifting  screw  is  shown  at  n,  on  the  left  of  the 
plate.  On  the  right  of  the  compass  circle  is  seen  the  head  of 
a  pinion  working  into  a  rack  fixed  to  the  edge  of  the  compass 
circle,  enabling  the  surveyor  to  move  it  about  its  center  in 
setting  off  the  magnetic  declination,  as  described  on  page 
115.  The  declination  is  read  to  single  minutes  by  a  vernier 
and  graduated  arc,  partially  shown  in  the  cut. 

A  clamp  screw  is  shown  at  r,  by  which  the  circle  may 
be  securely  fixed  when  moved  to  the  proper  position. 

The  telescopic  sight,  hereafter  described,  is  often  used  with 
the  Railroad  Compass  with  excellent  results. 

We   make    two    sizes   of    this   instrument,  with   needles 

respectively  five  and  five  and  one-half  inches  in  length.     The 

SIZES  AND      smaller  size,  including  the  brass  head  of  the 

WEIGHTS       staff,  weighs   thirteen   pounds,  and  the  larger 

size  weighs  about  fourteen  pounds. 

TO  USE  THE  RAILROAD  COMPASS 
The  Railroad  Compass  can  be  used  upon  the  common 
ball -spindle,  or  better  upon  the  tangent  ball,  placed  either  in 
a  staff  socket,  a  compass  tripod,  or  the  leveling-adopter  and 
tripod,  as  shown  on  page  131.  The  instrument  may  also  be 
used  upon  the  leveling-head  with  clamp  and  tangent  move- 
ment and  tripod,  and  this  is  preferable  to  any  other  support. 
(Seepage  132.) 

To  take  horizontal  angles :     Having  leveled  the  plate  and 

set  the  limb  at  zero,  fix  the  sights  upon  one  of  the  objects 

HORIZONTAL     selected,  and,  clamping  the  whole  instrument 

ANGLES          to  the  spindle,  unclamp  the  vernier  plate  and 

turn  it  with  the  hand  until  the  sights  are  brought  nearly  upon  the 


114 


RAILROAD    COMPASS 


Railroad  Compass,  with  two  verniers  to  limb,  5%-inch  needle,  aad  staff  mountings. 
Price,  $75.00. 


RAILROAD    COMPASS  115 

second  object ;  then  clamp  to  the  limb,  and  with  the  tangent 
screw  fix  them  precisely  upon  it.  The  number  of  degrees  and 
minutes  read  off  by  the  vernier  will  give  the  angle  between 
the  two  objects?  taken  from  the  center  of  the  instrument. 

It  will  be  understood  that  horizontal  angles  can  be  taken 
in  any  position  of  the  verniers  with  reference  to  the  zero 
point  of  the  limb.  We  have  given  that  above  as  being  the 
usual  method  and  the  one  least  liable  to  error. 

Where  extreme  accuracy  is  required,  it  is  advisable,  in 
this  and  other  instruments  which  have  two  verniers,  to  obtain 
the  readings  of  the  limb  from  both,  add  the  two  together  and 
halve  their  sum.  The  result  will  be  the  mean  of  the  two 
readings,  and  the  true  angle  between  the  points  observed. 

In  taking  horizontal  angles,  the  magnetic  bearings  of  the 

USE  OF          two  objects  are  often   noted,  and    thus  two 

THE  NEEDLE      separate  readings  of  the  same  angle,  one  by 

the  limb  and  the  other  by  the  needle,  are  obtained,  to  be 

used  as  checks  upon  each  other  to  prevent  mistakes. 

To  set  off  the  magnetic  declination  :  Having  leveled  the 
instrument,  set  the  limb  at  zero  and  place  the  sights  upon  the 
MAGNETIC  old  line,  note  the  reading  of  the  needle,  and 
DECLINATION  make  it  agree  with  that  given  in  the  field 
notes  of  the  former  survey  by  turning  the  compass  circle 
about  its  center  by  the  pinion  head.  Clamp  the  compass 
circle,  and  the  number  of  degrees  or  minutes  passed  over  by 
the  vernier  of  the  circle  will  be  the  change  of  magnetic 
declination  in  the  interval  between  the  two  surveys. 

To  survey  with  this  instrument,  the  operator  should  turn 
USING  THE  tne  south  end  of  the  compass  toward  his  per- 
COMPASS  Son,  and  having  brought  the  zeros  of  the  limb 
and  vernier  plate  in  line,  clamp  the  plates,  and  proceed  as 
directed  in  the  account  of  the  Vernier  Compass. 


116  RAILROAD   COMPASS 

It  will  be  remembered  that  lines  can  be  run  and  angles 
measured  by  the  graduated  limb  and  verniers,  independently 
of  the  needle;  and  in  places  where  local  attraction  is  mani- 
fested this  is  very  desirable. 

RAILROAD   COMPASS,   ONE  VERNIER    TO  LIMB 

This  instrument  is  essentially  like  that  just  described,  but 
of  somewhat  simpler  construction  in  its  sockets.  It  is  in 
every  way  accurate  and  reliable,  although  offered  at  a  price 
materially  lower  than  that  of  the  compass  with  two  verniers. 

We  make  but  one  size  of  this  instrument,  which  has  a  five 
and  one -half -inch  needle,  and  weighs  about  thirteen  pounds. 


VERNIER  COMPASS 


'T'HIS  instrument,  shown  on  page  118,  has  its  compass  cir- 
•*•  cle,  to  which  is  attached  a  vernier,  movable  about  its  cen- 
ter a  short  distance  in  either  direction,  enabling  the  surveyor 
to  set  the  zeros  of  the  circle  at  any  required  angle  with  the 
line  of  sights.  The  number  of  degrees  contained  in  this  angle, 
or  the  declination  of  the  needle,  is  read  off  by  the  vernier. 

The  compass  circle  is  graduated   to   half-degrees   on  its 

upper  surface,  the  whole -degree  marks  being  also  cut  down 

on  the  inside  circumference,  and  is  fig- 

COMPASS   CIRCLE 

ured  from  0  to  90  on  each  side  of  the 

line  of  zeros.      The  circle  and  face  of  the  compass  are  silvered. 

The  movement  of   the  circle  is  effected  either  by  a  tangent 

screw,   as   shown    in   the   cut,  or  by  a  concealed  rack  and 

pinion,  the  head  of  which  projects  from  the  under  side  of  the 

main  compass  plate.      When    the    declination    is   set   off   as 

described,  the  circle  is  fastened  in  its  position  by  a  clamp  screw. 

The  vernier   is  graduated   on    its   edge   into 

thirty  equal  parts,  and  figured  in  two  series  on 

each  side  of  the  middle  line. 

In  the  same  plane  with  the  vernier  is  an  arc  or  limb,  fixed 
to  the  main  plate  of  the  compass,  and  graduated  to  half- 
degrees.  Each  space  on  the  vernier  is  one  minute  shorter 
than  a  single  space  on  the  limb.  The  surfaces  of  both  vernier 
and  limb  are  silvered. 

The  spirit-levels  are  placed  at  right  angles  with  each  other 
so  as  to  level  the  plate  in  all  directions,  and  are 
balanced  upon  a  pivot   under   the  middle  of  the 
tube,  so  as  to  be  adjustable  by  a  screw-driver. 

117 


118 


VERNIER  COMPASS 


Vernier  Compass,  6-inch  needle,  with  staff  mountings. 
Price,  $40.00. 


VERNIER    COMPASS  119 

Underneath    the    main    plate   is   a   needle-lifting  screw 
which,    by   moving    a    concealed    spring, 

NEEDLE-LIFTER  ,  „       ,  ,  ,  ' 

raises  the  needle  from  the  pivot,  and  thus 
prevents  the  blunting  of  the  point  in  transportation. 

When  the  compass  is  not  in  use,  it  is  the  practice  of  many 
surveyors  to  let  down  the  needle  upon  the  point  of  the  center - 
pin,  and  allow  it  to  assume  its  position  in  the  magnetic 
meridian,  so  as  to  retain  its  polarity.  We  would  advise  that 
after  the  needle  has  settled  it  should  be  raised  against  the 
glass,  in  order  not  to  dull  the  point  of  the  center-pin. 

A  small  dial  plate,  having  an  index  turned  by  a  milled 
head  underneath,  is  used  with  this  and  other 

OUTKEEPER  .  ..        .          ,     .    .  ™ 

compasses  to  keep  tally  in  chaining.  The 
dial  is  figured  from  0  to  16,  the  index  being  moved  one  notch 
for  every  chain  run. 

A  brass  cover  is  fitted  over  the  glass  of 

BRASS   COVER          ,  7 • - 

the  compass,  and  serves  to  protect  it  from 
accident,  as  well  as  to  prevent  electric  disturbance. 

The   sights,   or  sight   vanes,    have  fine  slits   cut  through 

nearly  their  whole  length,  terminated  at  intervals  by  circular 

apertures,  through  which  the  object  sighted  upon 

is  more  readily  found.      Sometimes  a  horse  hair  or 

wire  is  substituted  for  half  the  slit,  and  placed  alternately  with 

it  on  opposite  sights. 

The  telescopic  sight  is  often  used  with  the  Vernier  Com- 
pass, and  its  adjustments  and  use  are  described  on  pages  133 
to  139. 

The  right  and  left  edges  of  the  north  sight  of  our  com- 
passes are  graduated  to  half-degrees  for  angles  of  elevation 
and    depression    respectively,    which    are 

TANGENT   SCALE 

read    from   corresponding  peep-holes  on 
the  south  sight. 


120  VERNIER   COMPASS 

The  cut  shows  the  eyepiece  and  graduations  for  angles  of 
elevation.  Those  for  angles  of  depression,  not  shown  in  this 
cut,  are  seen  in  the  cut  of  the  Plain  Compass. 

The  compass  is  fitted  to  a  spindle  made  slightly  conical, 

and  having  on  its  lower  end  a  ball  turned  perfectly  spherical, 

and  confined  in  a  socket  by  a  pressure   so 

BALL-SPINDLE        ,-    ,          u  ,        i     ,,  •,     • 

light  that  the  ball  can  be  moved  in  any 
direction  in  leveling  the  compass.  The  ball  is  placed  either 
in  the  brass  head  of  the  staff,  or  better  in  the  compass  tripod 
seen  in  the  cut  of  the  Vernier  Transit  on  page  53. 

A  leveling-adopter,  shown  on  page  131,  is  also  often  used 
for  more  convenient  leveling  of  the  compass. 

The  staff  mountings   consist  of   the  brass  head  already 

mentioned,  and  a  pointed  steel  shoe.     The  staff,  to  which  the 

mountings  should  be  securely  fastened, 

STAFF   MOUNTINGS  .  f  ,       .       .    , 

may  be  procured  from  any  wheelwright, 
or  provided  by  the  surveyor  himself. 

In  the  side  of  the  hollow  socket  of  the 

CLAMP   SCREW  .  ,  .    ,       ,        . 

compass  is  a  screw  by  which  the  instrument 
may  be  clamped  to  the  spindle  in  any  position. 

Besides  the  clamp   screw   there  is  fitted   to  the  sockets 
of   our  compasses  a  spring  catch,  which,  as  soon  as  the  in- 
strument is  set  upon  its  spindle,  slips  into  a 
groove,  and  thus  removes  all  danger  of  the 
instrument  falling  from  the  spindle  while  being  carried. 

We    make   three    sizes   of  the   Vernier  Compass,   having 

needles  respectively  four,  five,  and  six  inches  long,  the  main 

plates  being  respectively  twelve  and  one-half,  fifteen, 

and  fifteen  and  one-half  inches  long.     The  sights  of 

the  smallest  are  about  an  inch  shorter  than  the  others. 

In  the  four-  and  five-inch  Vernier  Compasses,  the  variation 
arc  is  within  the  compass  circle,  like  that  of  the  Railroad 


.    VERNIER   COMPASS  121 

Compass,  and  the  magnetic  declination  is  set  off  to  minutes 
by  a  pinion  head  underneath  the  plate,  this  arc  being  clamped 
by  a  screw  placed  opposite  the  pinion. 

The  average  weights  of  the  different  sizes,  including  the 
brass  head  of  the  staff,  are  respectively  six  and 

WEIGHTS  .    , 

one -quarter,    eight    and    three-quarters,    and    ten 
and  one -half  pounds. 

USE  OF   THE    VERNIER 

The  superiority  of  the  Vernier  over  the  Plain  Compass 
consists  in  its  adaptation  to  retracing  the  lines  of  an  old 
survey,  and  to  the  surveys  of  the  United  States  public  lands, 
in  which  the  lines  are  based  on  a  true  meridian. 

In  reading  the  vernier,  if  it  is  moved  to  the  right,  count 
the  minutes  from  its  zero  point  to  the  right,  and  vice  versa. 
TO  READ  THE  Proceed  thus  until  a  graduation  on  the 
VERNIER  vernier  is  found  exactly  in  line  with  another 
on  the  limb,  and  the  first  row  of  figures  on  the  vernier  will 
give  the  number  of  minutes  passed  over.  When  the  vernier 
is  moved  more  than  fifteen  minutes  to  either  side,  the  number 
of  additional  minutes,  up  to  thirty  or  one-half  degree  of  the 
limb,  is  given  by  the  second  row  of  figures  on  the  opposite 
side  of  the  vernier.  To  read  beyond  thirty,  add  the  minutes 
given  by  the  vernier  to  that  number,  and  the  sum  will  be  the 
correct  reading. 

In  all  cases  where  the  zero  point  of  the  vernier  passes  a 
whole  degree  of  the  limb,  this  must  be  added  to  the  minutes, 
in  order  to  ascertain  the  distance  over  which  the  vernier  has 
been  moved. 

It  is  well  known  that  the  magnetic  needle  deviates  more 

MAGNETIC         or  IGSS  to  ^e  east  or  west  of  a  true  meridian, 

DECLINATION       or  north   and   south  line.     This   deviation, 

which  is  called  the   magnetic  declination,  is   not    constant, 


122  VERNIER    COMPASS 

but  increases  or  decreases  to  a  very  sensible  degree  in  a  series 
of  years. 

Thus,  at  Troy,  N.  Y.,  a  line  bearing  in  1871,  N.  31°  E., 
would  in  1906,  with  the  same  needle,  have  a  bearing  of  about 
N.  33°  20'  E.,  the  needle  having  in  that  interval  traveled 
nearly  2°  20'  to  the  west. 

For  this  reason,  in  running  over  lines  from  field  notes  of 
some  years'  standing,  the  surveyor  is  obliged  to  make  an 
allowance,  both  perplexing  and  uncertain,  in  the  bearing  of 
every  line.  It  was  to  obviate  this  difficulty  that  the  Vernier 
Compass  was  devised. 

It  will  be  seen  that  the  surveyor  having  the  Vernier  Com- 
TO  SET  OFF  THE  P^8  can>  by  moving  the  vernier  to  either 
DECLINATION  side,  and  with  it,  of  course,  the  compass 
circle  attached,  set  the  compass  to  any  declination. 

He  therefore  places  his  instrument  on  some  well-defined 
line  of  the  old  survey,  and  turns  the  tangent  screw  until  the 
needle  of  his  compass  indicates  the  same  bearing  as  that 
given  in  the  field  notes  of  the.  original  survey.  Then,  clamp- 
ing the  vernier,  he  can  run  all  the  other  lines  from  the  old 
field  notes  without  further  alteration. 

The  reading  of  the  vernier  on  the  limb  in  such  a  case 
would  show  the  change  of  declination  of  the  two  different 
periods. 

The  magnetic  declination  at  any  place  being  known,  a 
true  meridian,  or  north  and  south  line,  may  be  run  by 
moving  the  vernier  to  either  side,  as  the  declination  is  east 
or  west,  until  the  arc  passed  over  on  the  limb  is  equal  to  the 
angle  of  declination,  and  then  turning  the  compass  until  the 
needle  is  made  to  cut  the  zeros  on  the  graduated  circle.  The 
line  of  sights  will  then  give  the  direction  of  the  true  meridian 
of  the  place. 


VERNIER   COMPASS  123 

Such  a  change  in  the  position  of  the  vernier  is  necessary 
in  surveying  the  United  States  public  lands,  which  surveys  are 
always  run  from  the  true  meridian. 

The  line  of  no  declination,  or  the  line  upon  which  the 
needle  will  indicate  a  true  north  and  south  direction,  is 
LINE  OF  NO  situated  in  the  United  States  nearly  in  an 
DECLINATION  imaginary  line  drawn  from  Sault  Ste.  Marie, 
Michigan,  to  Charleston,  South  Carolina.  A  magnetic  needle 
placed  east  of  this  line  has  a  declination  to  the  west,  and 
when  placed  west  of  the  line  the  declination  is  to  the  east ; 
and  in  both  cases  it  increases  as  the  needle  is  carried  farther 
from  the  line  of  no  declination. 

Thus,  in  Minnesota,  the  declination  is  from  eight  to 
eleven  degrees  to  the  east,  while  in  Maine  it  is  from  fifteen  to 
nineteen  degrees  to  the  west.  At  Troy,  in  the  year  1906, 
the  declination  is  about  11°  21 '  to  the  west,  and  is  increasing 
in  the  same  direction  about  three  minutes  annually. 

The  magnetic  declination  does  not  remain  constant 
through  an  entire  day,  but  reaches  its  farthest  point  east  about 
DIURNAL  8  o'clock  A.  M.,  and  its  farthest  point  west 
VARIATION  about  2  o'clock  P.  M.  The  cause  of  this  daily 
variation  of  the  needle  is  not  understood,  as  observations 
show  that  it  is  greater  in  summer  than  in  winter. 

Conditions  of  temperature,  magnetic  storms  and  other 
causes  at  times  affect  the  needle.  Our  own  experiments  show 
that  different  needles  observed  at  the  same  time  and  under  the 
same  conditions  differ  in  their  direction,  but  show  nearly  the 
same  daily  change. 

A  less  important  use  of  the  vernier  is  to  give  a  reading  of 

TO  READ         tne  needle  to    single  minutes,    which  is  ob- 

TO  MINUTES      tained  as  follows:     First   be   sure,  as  in    all 

observations,   that    the   zero    of    the    vernier   exactly    corre- 


124  VERNIER   COMPASS 

spends  with  that  of  the  limb.  Then,  noting  the  number 
of  whole  degrees  given  by  the  needle,  move  back  the  com- 
pass circle  with  the  tangent  screw  until  the  nearest  whole- 
degree  mark  is  made  to  coincide  with  the  point  of  the 
needle,  read  the  vernier  as  before  described,  and  this  reading 
added  to  the  whole  degrees  will  give  the  bearing  to  minutes. 

TO  ADJUST   THE  COMPASS 

To  adjust  the  levels:     Bring  the  level -bubbles   into  the 

middle  by  the  pressure  of  the  hand  on  different  parts  of  the 

.  plate,    and    turn    the    compass   half-way   around. 

Should  the  bubbles  run  to  the  end  of  the  tubes,  it 

would  indicate   that   those  ends  were   the   highest.     Lower 

them  by  loosening   the  screws   under  the  lowest  ends   and 

tightening  those  under  the  highest  ends  until,  by  estimation, 

the  error  is  half  removed.     Level  the  plate  again,  and  repeat 

the  first  operation  until  the  bubbles  will  remain  in  the  middle 

during  an  entire  revolution  of  the  compass. 

The  sights  may  next  be  tested  by  observing  through  the 

slits  a  hair  or  thread,  made  exactly  vertical  by  a  plummet. 

Should  the  hair  appear  on  the  side  of   the 

SIGHT  VANES          ..  .  ,  ...  ,  ... 

slit,  the  sight  must  *be  adjusted  by  filing  its 
under  surface  on  the  side  which  seems  the  highest. 
NEEDLE  ^°  adJust  tne  needle:     Having  the  eye  nearly 

in  the  same  plane  with  the  graduated  rim  of  the 
compass  circle,  with  a  splinter  of  wood  or  an  iron  wire  bring 
one  end  of  the  needle  in  line  with  any  prominent  graduation 
of  the  circle,  as  the  zero  or  the  ninety-degree  mark,  and 
notice  if  the  other  end  corresponds  with  the  degree  on  the 
opposite  side.  If  it  does  not,  bend  the  center-pin,  by  using 
the  small  brass  wrench  furnished  with  our  compasses,  about 
one-eighth  of  an  inch  below  the  point  of  the  pin,  until  the 


VERNIER   COMPASS  125 

ends  of  the  needle  are  brought  into  line  with  the  opposite 
degrees. 

Then,  holding  the  needle  in  the  same  position,  turn  the 
compass  half-way  aroupd,  and  note  whether  it  now  cuts 
opposite  degrees.  If  not,  correct  half  the  error  by  bending 
the  needle,  and  the  remainder  by  bending  the  center-pin. 
The  operation  should  be  repeated  until  perfect  reversion  is 
secured  in  the  first  position. 

This  being  obtained,  it  may  be  tried  on  another  quarter  of 
the  circle.  If  any  error  is  there  manifested,  the  correction 
must  be  made  in  the  center-pin  only,  the  needle  having  been 
already  straightened  by  the  previous  operation. 

When  again  made  to  cut,  it  should  be  tried  on  the  other 
quarters  of  the  circle,  and  corrections  made  in  the  same 
manner  until  the  error  is  entirely  removed,  and  the  needle 
will  reverse  in  every  point  of  the  graduated  surface. 

TO    USE    THE  COMPASS 

In  using  the  compass,  the  surveyor  should  keep  the  south 
end  toward  his  person,  and  read  the  bearings  from  the  north 
end  of  the  needle.  He  will  observe  that  the  E  and  W  letters 
on  the  face  of  the  compass  are  reversed  from  their  natural 
position,  in  order  that  the  direction  of  the  line  of  sight  may 
be  correctly  read. 

The  compass  circle  being  graduated  to  half-degrees,  a 
little  practice  will  enable  the  surveyor  to  read  the  bearings  to 
quarter -degrees  or  even  less,  estimating  with  his  eye  the  space 
bisected  by  the  point  of  the  needle ;  and  as  this  is  as  close  as 
the  traverse  table  is  usually  calculated,  it  is  the  general 
practice. 

Having  leveled  the  compass,  bring  the  south  end  toward 
the  person,  place  the  eye  at  the  little  button,  or  eyepiece,  on 


126  VERNIER    COMPASS 

the  right  side  of  the  south  sight,  and  with  the  hand  hold  a 
card  on  the  front  surface  of  the  north  sight,  so  that  its  top 
ANGLES  OF  edge  will  be  at  right  angles  with  the  graduated 
ELEVATION  edge  and  coincide  with  the  zero  mark.  Then, 
sighting  over  the  top  of  the  card,  note  upon  a  flagstaff,  held 
near  the  compass,  the  height  cut  by  the  line  of  sight,  move 
the  staff  up  the  elevation  and  carry  the  card  along  the  sight 
until  the  line  of  sight  again  cuts  the  same  height  on  the  staff. 
Read  off  the  degrees  and  half-degrees  passed  over  by  the  card, 
and  this  will  be  the  angle  required. 

ANGLES  OF        Proceed  in  the  same  manner,  using  the  eye- 
DEPRESSION       piece  and  graduations  on  the  opposite  side 
of  the  sight,  and  reading  from  the  top  of  the  sight. 
NEW  AND  OLD      When  the  compass  is  to  be  used  in  making 

SURVEYS  new  surveys,  the  vernier  should  be  set  at 
zero  and  clamped  by  the  nut  underneath  the  plate. 

In  surveying  old  lines,  the  change  of  the  magnetic  decli- 
nation should  be  ascertained  by  setting  the  compass  on  some 
well-defined  line  of  the  tract,  and  making  the  bearing  agree 
with  that  of  the  old  survey,  by  moving  the  circle  as  already 
described.  The  circle  can  then  be  clamped,  and  the  old 
lines  retraced  from  the  bearings  given  by  the  original  sur- 
veyor. 

When  the  magnetic  declination  is  known,  it  can  be  set  off 
by  the  vernier,  and  the  compass  used  to  run  a  true  meridian 
by  the  needle. 

Caution  should  be  exercised  in  handling  the  compass,  that 

the  glass  face  does  not  become  charged  with  electricity  excited 

by  the  friction  of  cloth,  silk,  or  the  hand,  so 

ELECTRICITY  ,.  .  ,  , 

as  to  attract  the  needle  to  its  under  surface. 
Should  the  glass  become  so  charged,  however,  the  electricity 
may  be  removed  by  breathing  upon  it,  or  by  touching  different 


VERNIER    COMPASS  127 

parts  of  its  surface  with  the  moistened  finger.  Ignorance  of 
this  apparently  trifling  matter  has  caused  the  inexperienced 
surveyor  much  annoyance. 

REPAIRS  TO    THE  COMPASS 

To  enable  the  surveyor  to  make  such  repairs  as  are  possible 
without  recourse  to  an  instrument  maker,  we  add  a  few  simple 
directions. 

The  magnetic  needle  is  the  most  vexatious  and  trouble- 
some part  of  a  surveyor's  instrument,  and  its  imperfect 
working  is  almost  invariably  due  to  a  roughened 

NEEDLE  ... 

or  scratched  jewel  or  to  a  dulled  center-pin,  or  to 
both,  and  rarely  to  loss  of  magnetism. 

A  wire  is  coiled  on  the  south  end  of  the  needle,  and  may 
be  moved  back  or  forth  to  counterbalance  the  varying  mag- 
netic attraction  at  the  north  end,  as  a  needle  which  is  perfectly 
balanced  in  one  locality  is  frequently  out  of  balance  in  a 
different  latitude. 

It  may  sometimes  happen  that  the  needle  has  lost  its 
polarity  and  must  be  remagnetized.  To  do  this,  proceed  as 
follows :  Unscrew  the  bezel  ring  that  holds  the  glass  face, 
and  remove  the  needle.  Pass  each  end  of  the  needle  from 
middle  to  extremity  with  a  gentle  pressure  over  the  magnetic 
pole  of  a  permanent  magnet,  describing  before  each  pass  a 
circle  of  about  six  inches  radius,  to  which  the  surface  of  the 
pole  is  tangent,  drawing  the  needle  toward  the  body,  and 
taking  care  that  the  north  and  the  south  ends  are  applied  to 
the  opposite  poles  of  the  magnet. 

Should  the  needle  be  returned  in  a  path  near  the  magnetic 
pole,  the  current  induced  by  the  contact  of  the  needle  with 
the  .magnet,  in  the  pass  just  described,  would  be  reversed, 
and  the  magnetic  virtue  almost  entirely  neutralized  at  each 


128  VERNIER    COMPASS 

operation.      When  the  needle  has  been  passed  in  this  manner 

aboj.it  twenty-five  times  in  succession,  it  will  be  fully  charged. 

The   center-pin  should   occasionally  be  examined,   and, 

if  much  dulled,  should  be  taken  out  with  the  brass  wrench  or 

with  a  pair  of  pliers,  and  sharpened  on  a  hard 

CENTER-PIN  .,  .... 

oilstone,  the  operator  placing  it  in  the  end  of 
a  small  stem  of  wood,  or  in  a  pin -vise,  and  delicately  twirling 
it  with  the  fingers  as  he  moves  it  back  and  forth  at  an  angle 
of  about  thirty  degrees  with  the  surface  of  the  stone. 

When  the  point  is  made  so  fine  and  sharp  as  to  be  invis- 
ible to  the  eye,  it  should  be  smoothed  by  rubbing  it  on  the 
surface  of  a  soft  and  clean  piece  of  leather. 

To  put  in  a  new  glass  :      Unscrew  the  bezel    ring,    and 

with    the  point  of  a    knife  blade  spring  out  the    brass   ring 

above    the    glass.      Remove    the    old    glass 

GLASS   CIRCLE  Tr 

and  scrape  out  the  putty.  If  the  new  glass 
does  not  fit,  smooth  off  its  edges  by  holding  it  obliquely 
against  the  surface  of  a  revolving  grindstone  until  it  will 
enter  the  ring  easily.  Put  in  new  putty  and  spring  in  the 
brass  ring. 

To  replace  a  level -vial :     Take  out  the  screws  which  hold 

the  level-tube  to  the  plate,  pull  off  the  brass  ends  of  the  tube, 

and  with  a  knife  blade  scrape  out  the  plaster 

from    the    tube.     Then    with   a   stick   a    little 

smaller  than  the  diameter  of  the  tube,  with  its  end  hollowed 

out    so    that   it  will  bear  only   on  the  broad  surface  of  the 

level-vial,  push  out  the  old  vial  and  replace  it  with  a  new 

one,  taking  care    that    the   crowning   side,  which    has  a  file 

mark  on  the  end  of  the  vial,  is  placed  on  the  upper  side. 

When  the  vial  does  not  fit  the  tube,  it  must  be  wedged 
by  putting  slips  of  paper  under  it,  until  it  moves  in  snugly. 

After  the  vial  is  in  its   place,  put  around  its  end  plaster 


VERNIER    COMPASS  129 

of  paris  mixed  with  water  to  the  consistency  of  putty,  taking 
care  not  to  cover  the  tip  of  the  glass,  and  slip  on  the  brass 
ends.  Melted  beeswax  dropped  upon  the  ends  of  the  vial  is 
quite  as  effective  as  the  plaster  of  paris,  and  often  more  easily 
obtained. 

An  extra  glass  and  level-vials  are  furnished,  free  of  charge, 
with  every  new  compass. 

See  also  Repairs  to  Compasses,  page  261. 


PLAIN  COMPASS 


NO.  232 

Price,  with  6-inch  needle  and  staff  mountings,  $35.00. 

*"TPHE  Plain  Compass  shown  in  the  cut  has  a  six-inch  needle, 
and  is  furnished  with  levels,  sight  vanes,  socket,  etc. 

The  compass  box  is  in  the  same  piece  with  the  main  plate, 
and  the  instrument  is  used  chiefly  in  the  surveys  of  new  lines, 
or  in  the  preparation  of  maps,  where  the  magnetic  declination 
is  not  required. 

We  make  three  sizes  of  this  instrument,  having  needles 
respectively  four,  five,  and  six  inches  long,  and  differing  also 
SIZES  AND  i*1  tne  length  of  the  main  plate,  which,  in  the 
WEIGHTS  four-inch  compass  is  twelve  and  one-half  inches 
long,  and  in  the  larger  sizes  fifteen  and  fifteen  and  one-half 
inches.  The  average  weights  of  the  different  sizes,  with  the 
brass  mountings  of  the  staff,  are  respectively  six,  seven  and 
three-quarters,  and  nine  and  one -half  pounds. 

130 


rLAIN  COMPASS 


131 


COMPOUND 
BALL-SPINDLE 


NO.  240 


NO.  241 


The  adjustments  and  use  of  the  Plain  Compass  are  sub- 
stantially the  same  as  those  of  the  Vernier  Compass  just 
described. 

We  manufacture  a  compound  ball-spindle, 
which  has  a  tangent  movement,  and  which 
gives  all  the  perfection  of  more  costly  arrangements  at  a  very 
moderate  expense. 

As  shown  in  the  cut,  No.  240,  it  has  an  interior  spindle, 
around  which  an  outside  hollow  cylinder  is  moved  by  turning 
the  double-headed  tangent,  which 
has  in  the  middle  a  screw,  working 
into  teeth  cut  spirally  around  the 
cylinder.  The  compass  or  other 
instrument  revolves  on  the  outside 
socket,  exactly  as  if  placed  on  a 
common  ball -spindle  ;  but  when  a 
slower  movement  is  desired,  it  can 
be  clamped  and  turned  gradually 
around  the  interior  spindle  by  the 
tangent  screw,  until  the  slit  of  the 
sight  or  the  intersection  of  the 
wires  is  brought  accurately  upon 
the  point  observed. 

When  the  compound  ball -spindle 
is  ordered  with  a  compass,  we  omit  the  plain  ball -spindle  and 
make  a  reduction  of  $2.00  from  the  price  of  the  instrument. 

Price  of  Compound  Ball-spindle $9.00 

LEVELING-  For  more  convenient  leveling  of   the  com- 

ADOPTER  pass,  as  well  as  other  instruments,  we  make  the 
leveling -adopter  shown  in  No.  241,  which  is  screwed  to 
the  top  of  the  tripod  like  the  leveling-head.  It  can  be  used 


132 


PLAIN  COMPASS 


either  with  a  simple  ball-spindle,  or  with  the  compound  ball 
with  tangent  screw,  as  shown  in  the  cut. 

The   instrument    is   made   approximately  level    upon  the 
ball,  and  finally  made  truly  horizontal  by  the  leveling-screws. 

Price  of   Leveling-Adopter,   without    tripod  or   ball- 
spindle  ;$  7.00 

With  tripod  and  Compound  Tangent  Ball,  as  shown.  .    21.00 

We   also   make    for   use   with   surveyors'    compasses  and 

vernier  tran-  LEVELING- 
sit  compasses  HEAD 
a  leveling-head,  consisting 
of  upper  and  lower  plates, 
four  leveling-screws,  and 
clamp  and  tangent  move- 
ment. See  Nos.  176  and 
242  of  the  Price  List. 

This  leveling-head 
furnishes  a  stable  support 
for  the  instrument,  and 
affords  the  same  c  o  n  - 
veniences  for  leveling  and 
accurate  adjustment  in  azi- 
muth as  the  leveling-heads 
on  the  more  expensive 
instruments. 


NOS.    176   AND   242 

LEVELING-HEAD 


Price   of  Leveling-head   complete  with   tripod,    and 

fitted  to  the  socket  of  Compass  or  Vernier  Transit.  .$18.00 
Without  the  tripod 13.00 


TELESCOPIC   SIGHT 


\\  7E  have  for  years  furnished  a  telescope  which  can  be 
attached  to  the  sight  vanes  of  compasses,  and  easily 
removed,  and  many  hundreds  of  these  attachments  are  now 
in  use  in  all  parts  of  the  country 

This  telescope  is  fitted  with 
cross-wires,  and  is  attached  to  a 
movable  band  which,  as  shown 
in  the  cut,  can  be  slipped  over 
the  sight  of  a  compass,  clamped 
at  any  point  desired,  and  ad- 
justed with  a  screw-driver  and 
a  steel  adjusting-pin. 

To  put  this  attachment  in 
place,  slip  the  band  over  the 
south  sight  of  the  compass,  hav- 
ing the  telescope  at  the  right 
hand  and  the  clamp  screw  on 
the  outer  surface  of  the  sight, 
placing  the  band  as  low  as  will 
allow  the  telescope  to  revolve 
without  striking  the  compass. 
This  place  should  be  marked  by 
a  line  across  the  sight,  or  by  a 
screw  or  pin  on  the  inner  surface 
of  the  sight,  that  the  band  may 

'        Price  of  Telescope  No.  261 ,  as  shown , 
be  Set  at    the  Same  point    in  Sub-    with  movable  band  for  attaching,  $1800. 

sequent  use. 

To  fasten  the  band  to  the  sight,  bring  up  the  clamp  screw 

133 


134  TELESCOPIC  SIGHT 

with  a  pressure  just  sufficient  to  hold  the  band  to.  its  place, 
tighten  the  screw  on  the  left  until  the  band  is  against  the 
right  edge  of  the  sight,  and  finally  tighten  the  clamp  screw. 

To  focus  the  telescope,  turn  the  end  of  the  eyepiece  until 
by  the  spiral  motion  of  the  tube  the  cross-wires  are  brought 
into  distinct  view.  The  objective  is  then  moved  in  either 
direction  by  the  pinion  on  the  side  of  the  telescope,  until  the 
object  is  clearly  seen. 

The  optical  axis  of  the  telescopic  sight  is  at  one  side  of 

the  line  of  sight  of  the  sight  vanes,  but  parallel  with  it.     The 

difference    between  a  sight  taken  with  the 

OPTICAL  AXIS  .  , 

sight  vanes  and  one  taken  with  the  telescope 
is,  at  a  distance  of  two  hundred  feet,  about  two  minutes ;  so 
small  that  it  may  be  disregarded  in  any  survey  made  with  the 
magnetic  needle.  If  all  the  lines  are  run  with  the  telescopic 
sight,  the  angles  measured  will  be  accurate,  as  even  this  slight 
difference  is  entirely  eliminated. 

When  desired,  the  telescopic  sight  may  be  mounted  upon 

an  offset  standard  with  counterpoise,   and  so  arranged    that 

the  line  of  sight  is    in    line  with  the 

OFFSET   STANDARD 

zeros  of  the  compass  circle.      When  in 

use  this  standard,  with  the  telescope  attached,  is  substituted 
for  the  south  sight  of  the  compass. 

Price  of  Offset  Standard,  with  Counterpoise $7.50 

When  furnished  with  a  new  instrument  the  telescope  is 
packed  in  the  box  with  the  compass,  but  it  can  be  safely  sent 
by  mail  to  any  part  of  the  country,  packed  in  a  case-  in  which 
it  may  be  kept  when  not  in  use. 

We    make    two   styles  of    the    tele- 

SIZES  AND   POWER 

scopic  sight,  Nos.  261  and  262  of  the 
Price    List.      The    telescopes   are    about    nine    inches    long 


TELESCOPIC  SIGHT 


135 


and  have  a  power  of  eighteen  to  twenty  diameters.  No.  262 
is  furnished  with  stadia  wires,  in  addition  to  the  plain 
cross-wires  used  in  the  other  telescope. 

The  attachments  of  vertical  circle  three  inches  in  diameter 
EXTRA  all(^   reading   to  five  minutes,   level  on  tele- 

ATTACHMENTs  scope  with  graduated  vial,  and  clamp  and 
tangent  to  axis,  maybe  used  with  either  of  these  telescopic 
sights.  Whenever  the  level  is  used,  it  is  necessary  that  the 
clamp  and  tangent  to  axis  be  added. 


Telescope  No.  262  with  levd,  and 

clamp  and  tangent. 
Price,  as  shown,  $30.00. 


136  TELESCOPIC-  SIGHT 

In  the  cut  on  page  135,  the  telescope  No.  262  is  shown 
fitted  with  a  level,  and  clamp  and  tangent.  For  simple 
sighting  the  level  and  circle  can,  of  course,  be  dispensed 
with,  but  in  the  use  of  the  stadia  the  tangent  movement  is 
very  desirable. 

When  measurements  are  to  be  recorded  in  chains 
and  links,  the  stadia  wires  should  be  made  to  cover  one 
foot  at  a  distance  of  sixty-six  feet ;  if  recorded  in  feet, 
the  wires  should  cover  one  foot  at  a  distance  of  one  hundred 
feet. 

The  rod  used  with  the  stadia  should  be  graduated  to  feet 
and  decimals  of  a  foot,  and  provided  with  two  targets,  one 
being  fixed  at  some  definite  point,  while  the  other  can  be 
moved  as  the  surveyor  requires,  the  distance  between 
the  two  targets  being  accurately  read  off  by  the  vernier  of 
the  movable  one.  A  self-reading  rod,  as  described  on 
pages  199  and  201,  may  be  used  without  target  for  short 
distances. 

In  using  the  stadia,  the  upper  wire  is  brought  by  the 
tangent  screw  precisely  upon  the  upper  or  stationary  target, 
while  the  lower  target  is  moved  up  or  down  until  the  lower 
wire  exactly  bisects  its  center  line,  when  the  rod  is  read  and 
the  distance  recorded. 

The  advantage  of  the  telescope  over  the  sight  vanes  is 
readily  apparent.  Much  longer  sights  can  be  taken,  either 
ADVANTAGE  OF  ^ore  or  back,  and  lines  run  up  and  down 
THE  TELESCOPE  steep  hillsides  with  the  same  facility  as 
on  level  ground,  and  with  more  accuracy,  and  with  great 
relief  to  the  eyes  of  the  surveyor,  often  severely  strained  by 
the  use  of  the  sight  vanes  of  the  compass.  Indeed,  it  may 
be  said  that  with  this  simple  attachment  every  compass  can 
be  transformed  into  a  transit  compass,  and  the  advantages 


TELESCOPIC  SIGHT  137 

of  the  telescope  brought  within  the  reach  of  every  surveyor, 
at  small  cost. 

PRICES   OF   TELESCOPIC    SIGHTS   AND   ATTACHMENTS 
No.  PRICE       POST. 

261  Nine-inch   Achromatic   Telescope,    power    about    20 

diameters $18.00    $0.45 

262  Same    Telescope    as    No.   261,    but    furnished   with 

stadia  wires  for  measuring  distances 20.00         .50 

We  add  to  new  telescopic  sights  the  following  extras,  at 
prices  annexed. 

No.  PRICK       POST. 

265  Vertical  Circle  with  vernier  to  five  minutes $5.00 

266  Level  on  Telescope. . : 5.00 

267  Clamp  and  Tangent  to  Telescope  axis 5.00 

268  Offset  Standard  with  Counterpoise,  to  bring  the  Tel- 

escope over  the  line  of  zeros 7.50    $0.50 

We  cannot  attach  the  extras,  Nos.  265,  266,  and  267,  to 
old  telescopes,  but  we  will  furnish  new  telescopic  sights  fitted 
with  these  attachments  and  will  take  the  old  telescopes  in 
exchange  at  a  fair  price. 

TO  ADJUST  THE  TELESCOPIC  SIGHT 

To  make  the  adjustments,  and  indeed  to  do  any  correct 
work  with  a  compass,  the  level -bubbles  should  remain  in  the 
middle  when  the  instrument  is  turned  upon  its  spindle,  and 
the  sights  should  trace  a  vertical  line  when  the  compass  is 
level. 

The  means  of  effecting  the  adjustments  will  be  understood 
by  the  engraving  on  page  133  and  the  outline  cut  on  page 
138,  the  former  showing  the  rear,  and  the  latter  the  front 
view  of  the  band  to  which  the  telescope  is  attached. 

To  make  the  telescope  axis  horizontal,  the  compass  being 
in  good  order,  first  bring  the  levels  into  the  middle  and  place 
the  band  in  position  upon  the  sight,  as  before  described. 


138 


TELESCOPIC  SIGHT 


Focus  the  telescope,  and  set  the  vertical  cross-wire  on  the 
TELESCOPE  edge  °f  a  building  distant  from  fifty  to  sixty 

AXIS  feet,  at  a  point  near  the  ground.      Clamp  the 

compass  to  the  spindle,  and  raise  the  telescope  to  the  top  of 
the  building.  If  the  wire  strikes  to  the  right  of  the  edge,  it 
shows  that  the  right  end  of  the  telescope  axis  is  the  lowest. 

To  raise  it,  loosen  the  screws, 
B  B,  C  C,  which  hold  the  piece 
containing  the  axis  of  the  tele- 
scope, and  by  the  screws,  D  D, 
the  lower  of  which  should  be  un- 
screwed and  the  upper  one  tight- 
ened, raise  the  telescope  until  the 
wire  will  follow  the  vertical  line. 

If  the  cross-  wire  strikes  to  the 
left  when  the  telescope  is  raised, 
proceed  exactly  the  reverse  in 
making  the  correction,  until  the 
wire  will  follow  the  edge  from  one 
end  to  the  other.  If  the  vertical  cross-wire  is  not  parallel 
with  the  edge,  loosen  the  capstan  -head  screws,  and  turn  the 
ring  by  the  screw  heads  until  the  correction  is  made  ;  then 
tighten  the  screws. 

To  bring  the  line  of  collimation  into  a  position  at  right 

LINE  OF          angles  with  the  axis  of  the  telescope,  so  that 

COLLIMATION      the    cross-wires  will    indicate   two  points  in 

opposite    directions   in    the   same    straight    line,    proceed   as 

directed  on  pages  22  to  24. 

Fmd  O1"  plaCC  tW°  °bJectS'  One  °n  Cach 

side  of  the  compass  and  from  three  hun- 
dred  to  four  hundred  feet  distant  from  it, 
which  the  sight  vanes  will  intersect.      Clamp  to  the  spindle 


ADJUSTMENT   OF 

TELESCOPE  TO 
THE  SIGHTS 


TELESCOPIC  SIGHT  139 

and  sight  through  the  telescope  at  either  of  the  objects.  If 
the  vertical  wire  strikes  to  the  right,  loosen  the  screws  B  B, 
and  screw  up  those  in  front,  marked  F  F,  the  ends  only  of 
which  are  shown  in  the  figure,  until  the  vertical  wire  bisects 
the  object,  looking  again  through  the  vanes  to  see  that  the 
same  object  is  seen  through  both  telescope  and  sights.  If  the 
cross-wire  should  strike  to  the  left  of  the  object,  proceed  in  a 
manner  exactly  the  reverse  until  the  error  is  corrected. 

This  adjustment  is  always  made  by  us  before  the  attach- 
ment leaves  our  hands,  and  need  not  be  disturbed  except  in 
case  of  accident  or  careless  interference  with  the  cross-wire 
screws ;  but  it  can  be  easily  made  by  any  surveyor  in  a  few 
moments  and  with  very  little  practice. 

When  the  adjustments  are  complete,  the  attachment  can 
be  put  in  place  on  the  sight,  and  removed  and  replaced 
again,  without  danger  of  derangement. 


SMALLER    FIELD-INSTRUMENTS 

POCKET  SOLAR  COMPASS 
POCKET  RAILROAD  COMPASS 
POCKET  VERNIER  COMPASS 
POCKET  PLAIN  COMPASS 
GEOLOGISTS'  COMPASS 
CLINOMETER  COMPASS 
MINERS'  DIP-NEEDLE  COMPASS 
DIAL  COMPASS 


POCKET  COMPASSES 


\X7E  manufacture  a  variety  of  small  instruments  which  are 
so  portable  and  at  the  same  time  so  efficient  that  they 
are  often  used,  in  preference  to  the  larger  ones,  for  preliminary 
or  reconnoissance  work. 

POCKET  SOLAR  COMPASS 


NO.  276 

Price  as  shown,  with  tripod,  $105.00. 
142 


POCKET  SOLAR   COMPASS     .  143 

The  Pocket  Solar  Compass  has  a  needle  three  inches  long 
and  a  limb  four  and  one-half  inches  in  diameter,  graduated 
to  half-degrees,  figured  one  row  0  to  180  each  way,  and  read- 
ing by  one  double  vernier  to  single  minutes. 

The  arrangement  of  the  plates  is  similar  to  that  of  the 
large  Solar  Compass,  the  lower  plate  carrying  the  sights 
PLATES  AND  revolving  around  the  upper  or  compass  plate, 
SIGHTS  to  which  are  attached  the  solar  parts,  levels, 
etc.  There  is  a  clamp  and  tangent  movement  to  the  hori- 
zontal limb  and  another  to  the  whole  instrument  about  its 
spindle,  both  now  made  with  an  opposing  spring. 

The  sights  are  about  four  and  one-half  inches  high,  the 
distance  between  them  being  nearly  seven  inches.  They 
have  a  slit  and  hair  in  half  their  height,  and  are  hinged  to 
fold  down  in  packing. 

The  compass  circle  is  arranged  with  a  pinion  and  is 
movable,  so  as  to  set  off  the  magnetic  declination  to  five 
minutes.  The  needle  has  a  lifting  lever  by  which  it  is  raised 
against  the  glass. 

The  solar  apparatus  is  attached  to  the  upper  plate,  and 
consists  of  the  usual  hour,  latitude,  and 

SOLAR    PARTS  ..  •      i       A      o 

declination  arcs,  marked  respectively  A,  C, 
and  B  in  the  cut  on  page  142,  with  an  arm,  F  F,  to  the  decli- 
nation arc,  carrying  the  solar  lenses  and  lines. 

The   latitude  arc  is   graduated    to  half- 

LATITUDE   ARC 

degrees,  and  reads  by  its  vernier  to  five 
minutes. 

DECLINATION  Tne  declination  arc  is  graduated  to  quar- 

ARC  ter-degrees,    and    reads     by   its   vernier    to 

single  minutes. 

The  hour  arc  is  graduated  on  its  inner  edge  into  hours 
and  twelfths,  or  spaces  of  five  minutes  of  time,  the  index  on 


144  .      rOCKET  SOLAR   COMPASS 

the  declination  arc  above  easily  enabling  one  to  read  single 
minutes    of     time.      The    hour    arc    is    made 

HOUR   ARC  .  , 

movable  upon  its  supporting  segment  to  either 
side,  its  outer  edge  being  also  graduated  on  the  middle  por- 
tion to  spaces  of  five  minutes  of  time,  and  read  by  a  vernier 
upon  the  segment  to  single  minutes.  In  this  way  the  equa- 
tion of  time  for  any  given  day  is  set  off  at  once,  and  the  time 
indicated  by  the  index  of  the  hour  arc  made  to  agree  with 
mean  time,  or  that  given  by  the  clock. 

The  solar    lenses   and    lines  are  placed  as  in  the    larger 
instruments,  the  declination  arc  beinej  also 

SOLAR   LENSES 

reversible  as  the  sun  changes  from  north 
to  south  of  the  equator. 

When  packed  in  the  case,  the  declination  arc  with  its  arm 
is  detached  from  the  hour  arc,  and  this,  together  with  the 
latitude  arc,  folds  close  to  the  compass  box. 

The  Pocket  Solar  Compass  is  used  either  upon  a  ball -spin- 
dle with  staff  mountings,  or  as  shown,  upon  a  light  tripod  like 
the  other  pocket  compasses,  and  often  with  a  small  leveling- 
head  with  clamp  and  tangent  screws. 

Sometimes  a  side  telescope  with  counterpoise  is  used  in 
addition  to  the  sight  vanes. 

The  adjustments  and  use  of  the  Pocket  Solar  Compass  are 

substantially  the  same  as  those  of  the  large  Solar  Compass  already 

described,  and  its  indications  are  so  accurate 

ADJUSTMENTS  .         ...       . 

that  it  will  give  the  true  meridian  within 
an  error  of  one  minute.  This  fact,  taken  in  connection  with 
the  deflection  of  the  magnetic  needle,  will  indicate  with  cer- 
tainty the  presence  and  direction  of  veins  of  magnetic  iron  ore. 
This  instrument  is  very  nearly  as  accurate  as  the  large 
Solar  Compass,  while  it  is  much  more  portable.  It  weighs, 
without  box  or  tripod,  four  and  three-quarters  pounds. 


POCKET  RAILROAD  COMPASS 


145 


NO.    285 

Price  as  shown,  with  tripod,  $45.00. 

POCKET  RAILROAD  COMPASS 

The  instrument  shown  is  a  one-vernier  Railroad  Compass 
in  miniature.  The  limb  is  five  inches  in  diameter,  graduated 
to  half -degrees,  figured  one  row  0  to  180  each  way,  and  reads 
by  vernier  to  single  minutes.  The  needle  is  three  and  one- 
half  inches  long,  and  the  magnetic  declination  can  be  set  off 
to  single  minutes. 


146  POCKET  RAILROAD   COMPASS 

This  instrument  has  the  improved  spring  tangei\t,  and  the 
vernier  is  placed  at  an  angle  of  thirty  degrees  with  the  line  of 
sights.  The  sights  fold  down  closely  for  convenience  in 
packing,  and  are  each  made  half  slit  and  half  hair,  so  that 
fore  and  back  sights  may  be  taken  without  turning  the  in- 
strument. 

The  Pocket  Railroad  Compass  can  be  used  for  a  great 
variety  of  work,  and,  with  light  extension  tripod,  is  especially 
adapted  for  surveys  of  mines,  where  angles  must  be  taken 
independently  of  the  needle. 

Price  of  Pocket  Railroad  Compass  No.  285,  with  staff  mountings.  .   $40.00 

"     "       "  "  "  "       "     with  light  tripod 45.00 

"     "       "  "  "  "       "     with  extension  tripod  .      50.00 

POCKET  RAILROAD   COMPASS   WITH   TELESCOPE 

In  the  cut  on  page  147  we  show  a  form  of  the  Pocket 
Railroad  Compass  which  is  adapted  to  receive  the  telescopic 
sight. 

The  plates  are  circular  and  the  sights  are  made  half  slit 
and  half  hair,  and  are  jointed  to  fold  down  close  to  the  glass. 
The  needle  is  four  and  one-half  inches  long,  and  there  is  an 
arc  with  vernier,  on  the  outside  of  the  compass  plate,  for  set- 
ting off  the  magnetic  declination. 

The  instrument  has  a  limb  about  four  inches  in  diameter, 
placed  inside  the  compass  circle,  and  reading  by  a  vernier  to 
single  minutes.  The  spindle  has  a  clamp  and  tangent  move- 
ment. 

The  sights  being  inclined  to  each  other,  as  shown,  a  short 
standard  is  secured  by  two  milled-head  screws  to  the  tops 
of  the  sights,  and  a  telescope  is  thus  placed  in  position, 
making  the  instrument  in  effect  a  very  light  Surveyors' 
Transit. 

The  attachments  of  vertical  circle,  level,  and  clamp  and 


POCKET  R.   K.   COMPASS  WITH  TELESCOPE       147 


NO. 293 

Price  as  shown,  $83.00. 


148      POCKET  R.   R.   COMPASS    WITH   TELESCOPE 

tangent,  as  shown  in  the  figure,  may  also  be  added,  fur- 
nishing the  means  for  taking  grades  and  running  levels 
with  accuracy  sufficient  for  the  common  practice  of  the 
surveyor. 

The  sights  are  placed  at  one  side  of  the  line  of  zeros,  and 
the  telescope  is  thus  brought  into  that  line  and  over  the  center 
of  the  instrument.  The  short  standard  can  be  detached  with 
the  telescope  and  placed  in  the  case,  or  easily  replaced  with- 
out deranging  the  adjustments. 

The  Pocket  Railroad  Compass  may  be  used  either  on  a 
staff  or  with  small  tripod,  and,  if  desired,  with  small  leveling- 
head,  as  shown. 

The  weights  of  the  Pocket  Railroad  Compasses,  including 
the  brass  mountings  of  the  staff,  but  without  tripod,  are  as 
follows : 

No.  285,  8£-inch  Compass,  about 4    Ibs. 

No.  288,  4|-inch  Compass,  about \\  " 

Nos.  291  and  292,  4^-inch  Compass,  about G|  " 

No.  293,  4£-inch  Compass,  about , 7|  " 

PRICES 

No. 

285  Pocket  Railroad  Compass,  one  vernier  to  limb,  limb  5 
inches  diameter,  reading  to  one  minute,  and  with  clamp 
and  tangent,  3^-inch  needle,  folding  sights,  two  levels 
and  staff  mountings  ;  see  page  145 $40.00 

288  Pocket  Railroad  Compass,  one  vernier  to  limb  inside  the 
compass  circle  and  reading  to  one  minute,  with  clamp 
and  tangent,  4^-inch  needle,  folding  sights,  two  levels 
and  staff  mountings oo.OO 

'291  Pocket  Railroad  Compass,  4j-inch  needle,  clamp  and  tan- 
gent to  limb,  limb  reading  to  one  minute,  clamp  and  tan- 
gent to  spindle,  and  fitted  with  our  Telescopic  Sight 
No.  261,  with  the  attachments  of  vertical  circle  to  five 
minutes,  level,  and  clamp  and  tangent  to  telescope  axis. 
.  Price,  including  tripod 76.00 

292  Same  as  above,  but  with  Telescopic  Sight,  No.  262 78.00 

293  "       "      «        «       «  "  «      No.     262,    and 

with  leveling-adopter,  as  shown  on  page  147 83.00 


POCKET   VERNIER   COMPASS 


149 


No.  300— Price  as 
shown,  3%-inch  needle, 
with  tripod,  $21. 00. 


No.  305— With  4 Vo 
inch  needle,  and  tripod 
$23.00. 


POCKET    VERNIER   COMPASS 

The  Pocket  Vernier  Compass  is  an  excellent  and  portable 
instrument  for  preliminary  work,  having  a  fine  needle  and  a 
vernier  and  clamping  nut,  by  which  the  sights  can  be  placed 
at  an  angle  with  the  line  of  zeros,  so  as  to  set  off  the  magnetic 
declination  as  with  the  Vernier  Compass. 

The  instrument  has  folding  sights,  two  levels  and  staff 
mountings,  and  is  packed  in  a  mahogany  case. 

We  make  two  sizes  of  the  Pocket  Vernier  Compass,  hav- 
ing needles  respectively  three  and  one-half  and  four  and  one- 
half  inches  long.  In  the  smaller  instrument  the  sights  have 
a  slit  in  the  south  vane  and  a  hair  in  the  north  vane,  for 
readily  finding  an  object ;  but  in  the  larger  size  the  sights  are 


150  POCKET   VERNIER    COMPASS 

made  half  slit  and  half  hair,  as  shown  on  page  145.  Both 
sizes  have  the  compass  circle  graduated  to  half-degrees.  In 
the  smaller  size  the  vernier  of  the  variation  arc  reads  to  five 
minutes,  and  in  the  larger  size  to  single  minutes.  The  instru- 
ment may  be  used  upon  a  light  tripod,  if  desired. 

When  so  ordered,  a  rack  movement  with  pinion  is  added, 
by  which  the  magnetic  declination  may  be  set  off  more 
readily. 

Price  of  Rack  and  Pinion  to  variation  arc $4.00 

The  compass  with  three  and  one -half  inch  needle  weighs 
about  one  and  three-quarters  pounds;  that  with  four  and  one- 
half  inch  needle  about  two  and  three-quarters  pounds. 

POCKET    VERNIER   COMPASS    WITH    TELESCOPE 

As  shown  on  page  151,  a  telescope  with  attached  vertical 
circle,  level,  and  clamp  and  tangent,  may  be  added  to  the 
sights  of  the  four  and  one -half  inch  Pocket  Vernier  Compass, 
making  this  little  instrument  practically  a  transit  compass  for 
land  surveying  and  reconnoissance,  capable  of  running  levels 
and  grades  with  accuracy  sufficient  for  ordinary  practice. 
The  sights  in  this  instrument  are  placed  at  one  side,  that  the 
telescope  may  be  directly  over  the  center,  and  the  instrument 
should  have  a  clamp  and  tangent  movement  to  the  spindle,  as 
shown  in  the  figure.  When  packed  for  transportation,  the 
telescope  and  support  are  detached  from  the  sights  and  packed 
separately  in  the  case.  Staff  mountings  are  always  furnished 
with  these  compasses,  and  a  light  tripod,  as  shown,  is  very 
generally  added. 

The  weight  of  compass  No.  312,  without  tripod,  is  about 
four  and  one-half  pounds,  and  the  tripod  weighs  about  four 
pounds. 


POCKET  VERNIER  COMPASS  WITH  TELESCOPE   151 


NO.  312 

'  Price,  complete  as  shown,  $63.00. 
No.  PRICES 

311  Pocket  Vernier  Compass,  4^-inch  needle,  with  clamp  and 

tangent  to  spindle,  and  fitted  with  our  Telescopic  Sight 
No.  261,  with  attachments  of  vertical  circle  to  o  minutes, 
level,  and  clamp  and  tangent  to  telescope  axis.  Price, 
including  tripod $61.00 

312  Same  as  above,  but  with  Telescopic  Sight  No.  262,  as  shown       63.00 


152  , 


POCKET  PLAIN  COMPASSES 


POCKET  PLAIN  COMPASSES 

Besides  the  Pocket  Vernier  Compass,  we  make  a  similar 
instrument  without  a  vernier, 
which  is  often  found  very  serv- 
iceable. The  Pocket  Plain 
Compasses  have  needles  two 
and  one-half  and  three  and 
}  one-half  inches  long,  and  are 
supplied  with  levels  and  staff 
mountings  or  not,  as  desired, 
as  described  in  the  Price  List 
on  page  278.  They  are  packed 
in  a  light  mahogany  case,  the 
sights  folding  down  close  to  the 

NOS.  316   AND  318  , 

Prices,  $10.00  and  $12.00.  glaSS. 

A  convenient  arrangement  is  shown  in  No.  327,  at  a,  for 

LEVELING-        use     with       Pocket 

ADOPTER  Compasses  Nos. 
275  to  319,  affording  in  connec- 
tion with  the  ball  a  rapid  and 
accurate  means  of  leveling  any 
of  the  smaller  instruments. 
The  attachment  weighs  less 
than  one  pound,  and  can  be 
placed  on  the  tripod  by  merely 
removing  the  brass  cap.  Its 

No   327  value  and  use  are   readily 

Price,  $5.00.  apparent. 


GEOLOGISTS'   COMPASS 
GEOLOGISTS1  COMPASS 

FOREST   SURVEY    PATTERN 


153 


NO.  335 

.Price,  as  shown,  $24.00. 

We  show  above  a  popular  instrument  for  topographical 
work,  known  as  the  Geologists'  Compass.  It  is  made  of 
aluminum  to  secure  lightness  of  weight,  and  has  a  needle  two 
and  five-eighths  inches  long  enclosed  with  its  compass  circle 
in  a  circular  box  set  upon  a  base  four  inches  square.  The 
edges  of  this  base  are  beveled  and  graduated,  two  for  a  tan- 
gent scale  and  the  other  two  with  scales  of  eighths  and  tenths 
of  inches.  The  compass  circle  is  made  movable,  and,  by  a 
vernier  attached  to  it  on  the  inside,  the  magnetic  declination 
can  be  set  off  to  five  minutes.  On  the  south  side  of  the  com- 
pass face  is  an  arc  of  one  hundred  and  eighty  degrees,  figured 


154 


CLINOMETER   COMPASS 


on  each  side  of  the  zero  line  from  0  to  90.  The  index  point, 
a  pendulum  hung  from  the  center-pin,  indicates  on  this  arc 
the  angle  of  slope  when  the  compass  is  placed  so  that  it  rests 
on  its  south  edge.  On  the  outside  of  the  box  containing  the 
compass  circle  is  a  movable  circle,  beveled  and  graduated  on 
its  upper  edge  and  figured  from  0  to  90,  and  having  at  each 
quadrant  a  slit  cut  for  sighting.  Two  folding  sights  are 
attached  to  the  edge  of  the  circular  box.  The  compass  is 
supported  on  a  simple  ball -spindle  and  socket  with  staff 
mountings,  and  is  packed  in  a  mahogany  box. 

CLINOMETER   COMPASS 


NO.  338 

Price,  as  shown,  $1C.     See  page  155. 


CLINOMETER    COMPASS  155 

CLINOMETER   COMPASS 

Another  form  of  pocket  compass  is  shown  on  page  154. 
It  is  made  of  brass,  and  is  known  as  the  Clinometer  Compass. 
It  has  a  needle  three  and  one-half  inches  long,  enclosed  with 
its  compass  circle  in  a  circular  box  set  upon  a  base  four  and 
one-half  inches  square.  On  one  edge  of  this  base  is  placed 
the  rectangular  side  upon  which  the  compass  may  be  set  in 
determining  grades. 

The  pendulum  swinging  from  the  center-pin  designates  by 
its  index  the  degree  of  slope  upon  the  graduated  arc  on  the 
compass  face.  Two  folding  sights  are  attached  to  the 
circular  box,  and  two  levels  are  placed  at  right  angles  with 
each  other  upon  the  base.  The  compass  is  supported  upon  a 
ball-spindle  and  socket  with  staff  mountings,  and  is  packed  in 
a  mahogany  box. 


156 


MINERS'   DIP-COMPASS 


MINERS'  OR  DIP-COMPASS 

The  Dip -compasses,  two  forms  of  which  are  shown  on  this 
page,  consist  essentially  of  a  magnetic  needle  so  suspended  as 
to  move  readily  in  a  vertical  direction,  the  angle  of  inclina- 
tion, or  dip,  being  measured  upon  the  graduated  rim  of  the 
compass  circle. 

When  in  use,  the  ring  or  bail  is  held  by  the  hand,  and 
the  compass  box  by  its  own  weight  assumes  a  vertical  position. 
It  must  be  held  in  the  plane  of  the  magnetic  meridian. 


NOS.  340  AND  341 

Price,  $16.00. 


NOS.  344  AND  345 

Price,  f  16.00  and  $20.00. 


MINERS*    DIP-COMPASS  157 

In  this  position  the  needle,  when  unaffected  by  the  attrac- 
tion of  iron,  assumes  a  horizontal  line,  as  shown  by  the  zeros 
of  the  circle.  When  brought  over  any  mass  of  magnetic  iron 
ore  it  dips,  and  thus  detects  the  presence  of  such  ore  with 
certainty. 

If  the  Miners'  Compass,  Nos.  340  or  341,  is  held  hori- 
zontal it  serves  as  an  ordinary  pocket  compass,  and  indicates 
the  magnetic  meridian,  in  the  plane  of  which  it  should  be 
held  when  used  to  ascertain  the  dip. 

Several  forms  of  this  instrument  are  made.  Those  shown 
as  Nos.  340  and  341,  with  a  three -inch  needle,  have  the  two 
sides  of  glass,  and  are  provided  with  a  stop  for  the  needle, 
which  is  moved  by  the  little  brass  knob  between  the  ends  of 
the  ring. 

The  Norwegian  Compass,  Nos.  344  and  345,  is  a  modifi- 
cation of  an  instrument  used  in  northern  Europe. 

It  has  a  needle  either  three  or  four  inches  long,  resting 
upon  a  single  vertical  pivot  so  as  to  move  freely  in  a  horizon- 
tal direction.  At  the  same  time,  being  attached  to  the  needle 
cap  by  two  delicate  pivots,  one  on  each  side,  it  is  free  to  dip 
like  the  needle  of  the  ordinary  Miners'  Compass. 

There  is  no  instrument  made  which  will  indicate  the 
presence  of  gold  or  silver. 

PRICES 

No.  PRICK  POST. 

340  Miners'  Compass,  3-inch  needle,  glass  on  both  sides, 

wood  box,  stop  to  needle $16.00     $0.25 

341  Miners'  Compass,  3-inch  needle,  glass  on  both  sides, 

brass  covers,  stop  to  needle 16.00         .35 

344  Norwegian   Compass,    3-inch   needle,    glass  on  both 

sides,  brass  covers 16.00         .35 

345  Same  as  No.  344,  but  with  4-inch  needle 20.00         .50 


158 


DIAL    COMPASS 
BRASS  DIAL   COMPASS 


NO.  348 

Price,  $18.00. 


This  instrument  has  a  needle  two  and  five -eighths  inches 
long,  and  with  its  compass  circle  is  enclosed  in  a  circular  box 
set  upon  a  base  four  inches  square,  three  edges  of  which  are 
chamfered  and  graduated,  the  one  on  the  W  side  of  the  com- 
pass into  inches  and  tenths  and  the  two  others  into  degrees 
and  half-degrees,  and  figured  from  a  center  on  the  southwest 
corner  of  the  base. 

The  compass  circle  is  movable,  in  order  to  set  off  the 
magnetic  declination,  and  has  a  vernier  attached  to  it  on  the 
inside,  by  which  a  graduated  arc  on  the  face  of  the  compass 
is  read  to  five  minutes. 


DIAL    COMPASS  159 

There  is  also  on  the  south  side  of  the  face  an  arc  of  one 
hundred  and  eighty  degrees,  figured  from  0  to  90  on  each 
side  of  the  south  or  zero  line  of  the  face. 

A  pendulum  with  index  point  hung  from  the  center-pin 
reads  this  arc  when  the  compass  is  set  up  vertical  on  the  raised 
south  edge,  thus  making  it  a  clinometer  or  slope-measurer. 

The  sight  is  hinged  to  fold  in  packing,  but  when  erect  it 
makes  taut  a  silk  thread,  attached  at  one  end  to  the  sight  and 
at  the  other  to  an  hour  circle  above  the  compass  glass,  at  an 
angle  with  the  plane  of  the  hour  circle  equal  to  that  of  the 
latitude  of  the  place  where  the  compass  is  used.  The  hour 
circle  is  graduated  for  any  required  latitude,  as  a  sun-dial, 
the  thread  serving  as  a  gnomon  to  give  apparent  time  with 
the  sun.  ^ 

The  Dial  Compass  is  extensively  used  in  this  country  in 
regions  where  there  is  local  attraction,  and  it  is  desirable  to 
have  a  simple  means  of  determining  the  meridian  independ- 
ently of  the  needle. 

This  can  be  easily  and  quickly  done  by  turning  the  com- 
pass, with  dial  graduated  for  the  latitude  of  the  place,  until 
the  shadow  of  the  thread  when  the  compass  is  held  level  indi- 
cates local  time  on  the  dial.  The  line  of  zeros  will  then  be 
in  the  meridian.  The  needle  may  be  set  to  the  meridian 
by  laying  off  the  magnetic  declination,  and  any  deflection  of 
the  needle  from  the  true  meridian  will  indicate  the  presence 
of  veins  of  magnetic  iron  ore. 

Extra  hour  circles,  graduated  for  any  latitude  and  to  fit 
the  same  compass,  can  be  furnished,  and  we  also  supply  staff 
mountings,  including  ball-spindle  and  socket,  when  desired. 

Price  of  extra  Hour  Circles,  each :<f>5.00 

Price  of  Staff  Mountings,  as  above 2.50 


160  DIAL    COMPASS 

ALUMINUM  DIAL    COMPASS 


NO.  350 

Price,  as  shown,  $30.00. 


The  illustration  shows  an  improved  form  of  the  Dial  Com- 
pass, made  of  aluminum,  and  differing  from  our  No.  348  in 
several  respects.  This  instrument  is  of  the  same  size  and  has 
the  same  parts  as  the  Dial  Compass  shown  on  page  158,  and 
has  in  addition  a  movable  circle  graduated  on  its  beveled 
edge  from  0  to  90  degrees.  At  each  quadrant  there  is  a  slit 
cut  for  sighting,  and  an  open  sight  is  furnished  with  the  com- 
pass, to  be  placed  upon  the  clinometer  base  when  desired, 
and  used  in  connection  with  the  regular  sight.  The  instru- 
ment is  mounted  upon  a  small  ball -spindle  and  socket  with 
staff  mountings,  and  is  packed  in  a  mahogany  box. 


LEVELING-INSTRUMENTS 

ENGINEERS'  Y  LEVELS 
ARCHITECTS'  Y  LEVELS 
DRAINAGE  LEVELS 


ENGINEERS'  Y  LEVELS 


the  different  varieties  of   leveling-instruments,  the  Y 
Level  is  universally  preferred  by  American  engineers,  j 
on  account  of  its  easy  adjustment  and  superior  accuracy. 

We  manufacture  five  sizes  of  Y  Levels,  having  telescopes 
twenty-two,  twenty,  eighteen,  fifteen,  and  twelve  inches  in  j 
length.     The  cut  on  page  163  shows  our  twenty -inch  Level.  ; 
The  telescope  has  near  its  ends  two  rings  of  bell  metal,  ^ 
turned  very  truly  and  of  precisely  the  same  diameter.      On 
these  rings  it  rotates  in  the  Ys,  or  it  can  be  I 

TELESCOPE  A_ 

clamped,     when     the    clips    of     the    Ys    are  ^ 
brought  down  upon  the  rings,  by  pushing  in  the  tapering  pins,  j 

The  telescope  has  a  rack  and  pinion  movement  to  both  j 
objective  and  eyepiece,  and  an  adjustment  for  centering  the  1 
eyepiece,  shown  at  A  A  in  the  sectional  view  on  page  164. 
The  arrangement  for  insuring  the  accurate  projection  of  the  ] 
objective  slide  is  also  shown  at  C,  in  the  same  cut.  Both  of } 
these  are  concealed  from  observation  and  disturbance  by  thin  j 
bands  which  screw  over  them. 

A  dust  guard  to  the  objective  slide  is  now  furnished  with  j 
our  eighteen,  twenty,  and  twenty -two -inch  Y  Levels,  without  ] 
extra  charge.  This  slide  is  a  decided  improvement  over  the  j 
shade  formerly  used.  If  specially  ordered,  it  can  also  be  I 
placed  upon  our  fifteen -inch  and  Architects'  Levels. 

Price  of  Dust  Guard,  to  order,  as  above $4.00 

The   telescopes  of    our   Y    Levels,   like  I 

SHORT   FOCUS          .  , 

those  of  our  transits,  are  now  arranged  I 
so  that  they  may  be  focused  upon  an  object  much  I 
nearer  the  instrument  than  as  formerly  made.  Thus! 

162 


ENGINEERS*  LE  VELS 


NO. 376 

20-INCH   Y   LEVEL 
Price,  as  shown,  including  Tripod,  $110.00. 


164 


ENGINEERS'  LEVELS 


SECTIONAL  VIEW  OF  Y  LEVEL 


ENGINEERS*    LEVELS  165 

the  telescope  of  our  fifteen -inch  Level  can  be  focused  upon 
an  object  only  seven  and  one-half  feet  in  front  of  the  center 
of  the  instrument,  that  of  the  eighteen -inch  Level  upon  an 
object  eight  and  one-half  feet  distant,  that  of  the  twenty-inch 
Level  upon  an  object  ten  feet  distant,  and  that  of  the  twenty- 
two-inch  Level  upon  an  object  twelve  and  one-half  feet 
distant  from  the  center  of  the  instrument. 

A  small  compass,  with  three -inch  needle  and 
without  sights,  is  sometimes  attached  to  the  tele- 
scope and  used  to  obtain  the  bearing  of  lines. 

Price  of  attached  Compass $10.00 

A  horizontal  circle  three  and  one -half  inches  in  diameter 
HORIZONTAL      can  ^e  fitted  to  the  leveling-head  of   the   Y 
CIRCLE  Level.     The  circle  is  graduated   to   degrees, 

and  is  read  by  vernier  to  five  minutes. 

Price  of  Horizontal  Circle,  as  above $15.00 

The  interior  construction  of  the  telescope  will  be  under- 
stood from  the  sectional  cut  on  page  164,  which  shows  the 
OBJECTIVE  adjustment  which  insures  the  accurate  projection 
SLIDE  of  the  objective  slide.  This  is  peculiar  to  our 
instruments,  and  is  always  made  so  perfectly  that  it  needs  no 
attention  from  the  engineer. 

The  necessity  for  such  an  adjustment  will  appear  when  we 
state  that  it  is  almost  impossible  to  make  a  telescope  tube  a 
perfect  cylinder  on  its  inner  surface.  It  is  evident,  there- 
fore, that  the  objective  slide  which  is  fitted  to  this  surface, 
and  moves  in  it,  must  partake  of  its  irregularity,  so  that  the 
objective  and  the  line  of  collimation  dependent  upon  it, 
though  adjusted  in  one  position  of  the  slide,  will  be  thrown 
out  when  the  slide  is  moved  out  or  in. 

To  prove  this,  let  any  level  be  selected  which  is  con- 
structed in  the  usual  manner,  and  the  line  of  collimation 


166  ENGINEERS'   LEVELS 

adjustment  be  made  upon  an  object  as  near  as  the  range  of 
the  slide  will  allow.  Then  let  another  object  be  selected  as 
distant  as  may  be  clearly  seen  ;  upon  this  rotate  the  wires,  and 
they  will  generally  be  found  out  of  adjustment,  sometimes  to 
a  degree  fatal  to  any  confidence  in  the  accuracy  of  the 
instrument.  The  arrangement  adopted  by  us  to  correct  this 
imperfection,  and  which  perfectly  accomplishes  its  purpose,  is 
shown  in  the  sectional  cut. 

Here  are  seen  the  two  bearings  of  the  objective  slide,  one 
being  in  the  narrow  ring  slightly  less  in  diameter  than  the 
main  tube,  the  other  in  the  adjustable  ring  shown  at  C, 
suspended  in  the  middle  of  the  telescope  by  four  screws. 

Advantage  is  here  taken  of  the  fact  that  the  rays  of  light 
are  converged  by  the  objective,  so  that  none  are  obstructed 
by  the  contraction  of  the  slide  except  those  which  diverge, 
and  which  ought  always  to  be  intercepted  and  absorbed  in  the 
blackened  surface  of  the  interior  of  the  slide. 

In  such  a  telescope  the  perfection  of  movement  of  the 
slide  depends  entirely  upon  its  exterior  surfaces  at  the  point 
of  the  two  bearings.  These  surfaces  are  accurately  turned, 
concentric  and  parallel  with  each  other,  and,  being  fitted  to 
the  rings,  it  is  only  necessary  to  adjust  the  position  of  the 
smaller  ring  so  that  its  center  will  be  coincident  with  the 
optical  axis  of  the  objective.  When  this  has  been  done  no 
further  correction  will  be  necessary,  unless  the  telescope 
should  be  severely  injured.  The  manner  in  which  the  adjust- 
ment of  the  objective  slide  is  effected  will  be  considered  when 
we  speak  of  the  other  adjustments. 

As  seen  in  the  cut,  the  telescopes  of  our  eighteen, 
RACK  AND  twenty,  and  twenty-two-inch  Levels  are  furnished 
PINION  with  rack  and  pinion  movement  to  both  objec- 
tive and  eyepiece. 


ENGINEERS'   LEVELS  167 

The  advantages  of  an  eyepiece  pinion  are  that  the  eye- 
piece can  be  moved  without  danger  of  disturbing  the  tele- 
scope, and  that  the  wires  are  more  certainly  brought  into 
distinct  view,  so  as  to  avoid  any  error  of  observation  arising 
from  the  instrumental  parallax. 

The  level-tube,  with  ground  vial  and  a  scale,  is  attached" 
to  the  under  side  of  the  telescope,  and 

LEVEL-VIAL  ...  ,         .  . 

furnished  at  different  ends  with  the  usual  move- 
ments in  both  horizontal  and  vertical  directions. 

The  aperture  of  the  tube,  through  which  the  glass  vial  is 
seen,  is  about  five  and  one-quarter  inches  long,  and  is  crossed 
at  the  middle  by  a  rib  or  bridge  which  greatly  strengthens  the 
tube. 

The  level -vial  is  a  glass  tube  with  an  even  bore  from  end 
to  end,  and  finely  ground  on  its  inner  surface,  so  that  the  run 
of  the  air  bubble  may  be  uniform  throughout  its  whole  range. 
The  level -scale,  which  extends  over  the  whole  length  and  is 
set  close  to  the  glass,  is  graduated  to  tenths  of  an  inch  and 
figured  in  each  direction  at  every  fifth  division,  from  0  at  the 
middle  of  the  bridge. 

The  sensitiveness  of  a  ground  level  is  best  determined  by 
an  instrument  called  a  level -tester,  consisting  of  a  bar  with 
two  Ys  to  hold  the  level -tube,  and  pivoted  at  one  end,  while 
at  the  other  end  is  a  micrometer  wheel  attached  to  the  top  of 
a  fine  threaded  screw  which  raises  the  end  of  the  tester  very 
gradually.  The  number  of  divisions  passed  over  on  the 
perimeter  of  the  wheel,  in  carrying  the  bubble  over  a  tenth 
of  an  inch  on  the  scale,  is  the  index  of  the  delicacy  of  the 
level.  In  the  tester  which  we  use,  a  movement  of  ten  divi- 
sions of  the  wheel  to  one  of  the  scale  indicates  the  degree  of 
delicacy  generally  preferred  for  railroad  engineering.  For 
canal  work  a  more  sensitive  bubble  is  often  required,  as,  for 


168  ENGINEERS'    LEVELS 

instance,  one  of  five  to  seven  divisions  of  the  wheel  to  one  of 
the  scale. 

The  Ys  of  our  levels  are  large  and  strong,  of  the  best  bell 
metal,  and  each  has  two  nuts  adjustable  with  the  steel  pin. 
The  clips  are  brought  down  on  the  rings  of  the  telescope 
tube  by  the  Y  pins,  which  are  tapering  so  as  to  clamp 
the  rings  firmly.  The  clip  of  one  of  the  Ys  has  a  pin  project- 
ing from  it,  which,  entering  a  recess  in  the  edge  of  the  ring, 
insures  the  horizontal  position  of  the  cross-wire. 

The  level-bar  is  round,  of  the  best  bell  metal,  and 
'  shaped  for  greatest  strength  in  the  parts  most 
liable  to  sudden  strains.  Connected  with  the 
level-bar  is  the  head  of  the  leveling-socket. 

The   socket   is   compound.     The  inner   spindle,   D  (see 

page  164),  upon  which  the  whole  instrument  is  supported,  is 

of    steel,    nicely   ground    so    as    to    turn    evenly 

and    firmly  in  a   hollow  cylinder  of  bell    metal ; 

this  again  has  its  exterior  surface  fitted  and    ground  to  the 

main  socket,  E  E,  of  the  leveling-head. 

The  cylinder  is  held  upon  the  spindle  by  a  washer 
and  screw,  the  head  of  the  latter  having  a  hole  in  its  center 
through  which  the  string  of  the  plummet  is  passed. 

The  upper  part  of  the  instrument,  with  the  socket,  may 
be  detached  from  the  leveling-head,  and  this  also,  as  is  the 
case  with  all  our  instruments,  can  be  unscrewed  from  the 
tripod  head;  but  all  our  Y  Levels  are  packed  in  the  case 
complete  with  leveling-head,  experience  having  shown  that 
there  is  thus  less  danger  of  injury  in  transportation.  It  will 
be  seen  from  the  cut  that  the  arrangement  just  described  allows 
long  sockets,  and  yet  brings  the  whole  instrument  down  as 
close  as  possible  to  the  leveling-head,  both  objects  of  great 
importance  in  the  construction  of  any  instrument. 


ENGINEERS'    LEVELS  169 

The  leveling- head  has  the  same  plates  and  leveling-screws 
LEVELING-  as  described  in  the  account  of  the  transit  (see 
HEAD  page  19).  The  tangent  screw  has  also  an 
opposing  spring,  as  there  described. 

For  the  fifteen -inch  Level  we  make  a  leveling -head  similar 
to  that  used  with  the  lighter  Engineers'  Transit. 

TO  ADJUST    THE  LEVEL 

The  adjustment  of  the  objective  slide  is  peculiar  to  our 
instruments,  and  is  always  made  by  us  so  permanently  as  to 
need  no  attention  at  the  hands  of  the  engineer,  unless  in  case 
of  derangement  by  accident. 

To  adjust  the  objective  slide,  the  maker  selects  an  object 
as  distant  as  may  be  distinctly  observed,  and  upon  it  adjusts 
OBJECTIVE  tne  lme  °f  collimation,  in  the  manner  described 
SLIDE  on  page  171,  making  the  intersection  of  the 
wires  to  rotate  without  passing  either  above  or  below  the 
point  or  line  selected.  In  this  position  the  slide  will  be 
drawn  in  nearly  as  far  as  the  telescope  tube  will  allow. 

With  the  pinion  head  he  then  moves  out  the  slide  until 
an  object,  distant  about  ten. or  fifteen  feet,  is  brought  clearly 
into  view.  Again  rotating  the  telescope  in  the  Ys,  he  observes 
whether  the  wires  will  reverse  upon  this  second  object. 

Should  this  be  the  case,  he  will  assume  that,  as  the  line  of 
collimation  is  in  adjustment  for  these  two  distances,  it  will  be 
for  all  intermediate  ones,  since  the  bearings  of  the  slide  are 
supposed  to  be  true  and  their  surfaces  parallel  with  each  other. 

If,  however,  either  or  both  wires  fail  to  reverse  upon  the 
second  point,  he  must,  by  estimation,  remove  half  the  error 
by  the  screws  at  C  (see  page  164),  at  right  angles  with  the 
wire  to  be  corrected,  remembering  that,  on  account  of  the 
inverting  power  of  the  eyepiece,  he  must  move  the  slide  in 


170  ENGINEERS'  LEVELS 

the  direction  which  apparently  increases  the  error.  When 
both  wires  have  been  thus  treated,  the  line  of  collimation  is 
adjusted  on  the  near  object,  and  the  telescope  again  brought 
upon  the  most  distant  point.  The  tube  is  again  rotated,  the 
reversion  of  the  wires  upon  the  object  once  more  tested,  and 
the  correction,  if  necessary,  made  in  the  same  manner. 

He  proceeds  thus  until  the  wires  will  reverse  upon  both 
objects  in  succession  ;  the  line  of  collimation  will  then  be  in 
adjustment  at  these  and  all  intermediate  points.  By  bringing 
the  screw  heads  to  a  firm  bearing  upon  the  washers  beneath 
them,  the  adjustable  ring  will  be  fastened  so  as  to  need  no 
further  attention  for  many  years.  The  thin  brass  ferule  is 
then  screwed  over  the  outside  ring,  concealing  the  screw 
heads  and  obviating  all  danger  of  their  disturbance. 

In  making  this  adjustment,  it  is  always  best  to  bring  the 
wires  into  the  center  of  the  field  of  view  by  moving  the 
screws  A  A,  see  page  164,  working  in  the  centering-ring  of 
the  eyepiece  tube. 

Should  the  engineer  desire  to  make  the  adjustment  of  the 
objective  slide,  it  will  be  necessary  to  remove  the  level -tube, 
in  order  that  the  screw  immediately  above  its  scale  may  be 
accessible. 

The  adjustments  which  are  common  to  all  Y  Levels,  and 
with  which  the  engineer  should  be  familiar,  are  : 

To  adjust  the  line  of  collimation,  or,  in  other  words,  to 
bring  the  cross-wires  into  the  longitudinal  axis,  so  that  their 
point  of  intersection  will  remain  on  any  given  point  during  an 
entire  rotation  of  the  telescope. 

To  bring  the  level-bubble  parallel  with  the  bearings  of 
the  Y  rings,  or  with  the  longitudinal  axis  of  the  telescope. 

To  adjust  the  Ys,  or  to  bring  the  bubble  into  a  position  at 
right  angles  with  the  vertical  axis  of  the  instrument. 


ENGINEERS'   LEVELS  171 

To  adjust  the  line  of  collimation  :  Set  the  tripod  firmly, 
remove  the  Y  pins  from  the  clips  so  as  to  allow  the  telescope 
LINE  OF  to  turn  freely,  clamp  the  instrument  to  the 
COLLIMATION  leveling-head,  and  by  the  leveling  and 
tangent  screws  bring  either  of  the  wires  upon  the  clearly 
marked  edge  of  some  object,  distant  from  one  hundred  to 
five  hundred  feet.  Then  with  the  hand  carefully  rotate  the 
telescope  half-way  around,  so  that  the  position  of  the  same 
wire  is  compared  with  the  object  selected. 

Should  it  be  found  above  or  below,  bring  it  half-way  back 
by  the  capstan -head  screws  at  right  angles  with  it,  always 
remembering  the  inverting  property  of  the  eyepiece ;  bring 
the  wire  again  upon  the  object  and  repeat  the  first  operation 
until  it  will  reverse  correctly.  Proceed  in  the  same  manner 
with  the  other  wire  until  the  adjustment  is  complete.  Should 
both  wires  be  much  out,  it  will  be  well  to  bring  both  nearly 
correct  before  either  is  entirely  adjusted. 

When  this  is  effected,  unscrew  the  covering  of  the  eye- 
piece centering-screws,  shown  in  the  sectional  view  at  A  A, 
page  164,  and  move  each  pair  in  succession  with  a  screw- 
driver until  the  wires  are  brought  into  the  center  of  the  field 
of  view.  The  inverting  property  of  the  eyepiece  does  not 
affect  this  operation,  and  the  screws  are  moved  directly. 

To  test  the  correctness  of  the  centering,  rotate  the 
telescope,  and  observe  whether  it  appears  to  shift  the  position 
of  an  object.  Should  any  movement  be  apparent,  the 
centering  is  not  perfectly  effected.  In  all  telescopes  the 
line  of  collimation  depends  upon  the  relation  of  the  cross - 
wires  and  objective,  and  therefore  the  movement  of  the 
eyepiece  does  not  affect  the  adjustment  of  the  wires  in  any 
respect. 

When  the  centering  has  once  been  effected  it  remains 
>< 


£        \> 
f  t*^ 

I  UNIVERSITY  ) 

V  ric-  / 


172  ENGINEERS*   LEVELS 

permanent,  the  cover  being  screwed  on  again  to  protect  it 
from  derangement. 

To  adjust  the  level -bubble :     Clamp  the  instrument  over 

either   pair  of  leveling -screws,  and   bring    the   bubble    into 

the  middle  of   the  tube.     Turn   the  telescope 

LEVEL-VIAL  ,       A7  ,     .  1111 

in  the  Ys,  so  as  to  bring  the  level -tube  to  one 
side  of  the  middle  of  the  bar.  Should  the  bubble  run  to 
the  end,  it  would  indicate  that  the  vertical  plane  passing 
through  the  middle  of  the  bubble  was  not  parallel  with  that 
drawn  through  the  axis  of  the  telescope  rings. 

To  correct  the  error,  bring  the  bubble,  by  estimation, 
half-way  back  by  the  capstan -head  screws  on  each  side  of 
the  level -holder,  placed  usually  at  the  objective  end  of  the 
tube.  Again  bring  the  level -tube  over  the  middle  of  the 
bar  and  the  bubble  to  the  middle,  turn  the  level  to  either 
side,  and,  if  necessary,  repeat  the  operation  until  the  bubble 
will  keep  its  position  when  the  tube  is  turned  half  an  inch  or 
more  to  either  side  of  the  middle  of  the  bar. 

The  necessity  for  this  operation  arises  from  the  fact  that, 
when  the  telescope  is  reversed  end  for  end  in  the  Ys  in  the 
other  and  principal  adjustment  of  the  bubble,  we  are  not  cer- 
tain of  placing  the  level -tube  in  the  same  vertical  plane,  and 
therefore  it  would  be  almost  impossible  to  effect  the  adjust- 
ment without  a  lateral  correction. 

Having  now  largely  removed  the  initial  difficulties,  we 
proceed  to  make  the  level-tube  parallel  with  the  bearings  of 
the  Y  rings. 

To  do  this,  bring  the  bubble  into  the  middle  with  the  level- 
ing-screws,  and  then,  without  jarring  the  instrument,  take  the 
telescope  out  of  the  Ys  and  reverse  it  end  for  end.  Should  the 
bubble  run  to  either  end,  lower  that  end,  or,  what  is  equiva- 
lent, raise  the  other  by  turning  the  adjusting-nuts  on  one  end 


ENGWEERS'   LEVELS  173 

of  the  level  until,  by  estimation,  half  the  correction  is 
made.  Again  bring  the  bubble  into  the  middle  by  the 
leveling-screws,  and  repeat  the  whole  operation  until  the 
reversion  can  be  made  without  causing  any  change  in  the 
bubble. 

It  would  be  well  to  test  the  lateral  adjustment  and  make 
such  correction  as  may  be  necessary  in  that,  before  the  hori- 
zontal adjustment  is  entirely  completed. 

To  adjust  the  Ys:  Having  made  the  previous  adjust- 
ments, it  remains  to  bring  the  level  into  position  at 
right  angles  with  the  vertical  axis,  so  that  the  bubble 
will  remain  in  the  middle  during  an  entire  revolution  of  the 
instrument. 

To  do  this,  bring  the  level -tube  directly  over  the  middle 
of  the  bar  and  clamp  the  telescope  in  the  Ys,  placing  it  as 
before,  over  two  of  the  leveling-screws.  Unclamp  the  socket, 
center  the  bubble,  and  turn  the  instrument  half-way  around, 
so  that  the  level -bar  may  occupy  the  reverse  position  in  respect 
to  the  leveling-screws  beneath. 

Should  the  bubble  run  to  either  end,  bring  it  half-way 
back  by  the  Y  nuts  on  either  end  of  the  bar.  Place  the  tele- 
scope over  the  other  pair  of  leveling-screws,  bring  the  bubble 
again  into  the  middle,  and  proceed  as  above  described, 
changing  to  each  pair  of  screws  successively  until  the  adjust- 
ment is  very  nearly  perfected,  when  it  may  be  completed  over 
a  single  pair. 

The  object  of  this  approximate  adjustment  is  to  bring  the 
upper  plate  of  the  leveling-head  into  a  position  as  nearly 
horizontal  as  possible,  in  order  that  no  essential  error  may 
arise  in  case  the  level,  when  reversed,  is  not  brought  opposite 
its  former  position.  When  the  level  has  been  thus  completely 
adjusted,  if  the  instrument  is  properly  made  and  the  socket 


174  ENGINEERS'  LEVELS 

well  fitted,  the  bubble  will  reverse  over  each  pair  of  screws 
in  any  position. 

Should  the  engineer  be  unable  to  make  it  work  correctly, 
he  should  examine  the  outside  socket  to  see  that  it  is  set 
securely  in  the  main  socket,  and  also  notice  that  the  clamp 
does  not  bear  upon  the  ring  which  it  encircles.  When  these 
are  correct,  and  the  error  is  still  manifest,  it  will  probably  be 
found  in  the  imperfection  of  the  interior  spindle. 

The  adjustments  having  been  completed,  and  the  instru- 
ment being  precisely  level,  the  engineer  should  rotate 
the  telescope  in,  the  Ys  until  the  pin  on  the  clip  of  the 
Y  will  enter  the  little  recess  in  the  ring  to  which  it  is 
fitted,  and  by  which  the  horizontal  position  of  the  cross - 
wire  is  insured. 

When  the  pin  is  in  its  place  the  horizontal  wire  may  be 
compared  with  any  level  line,  and  in  case  it  should  not  be 
parallel  with  it,  two  of  the  cross-wire  screws  that  are  at  right 
angles  with  each  other  may  be  loosened  and,  by  the  screws 
outside,  the  cross-wire  ring  turned  until  the  wire  is  horizontal. 
The  line  of  collimation  must  then  be  corrected  again,  and  the 
adjustments  of  the  level  will  be  complete. 

TO    USE    THE  LEVEL 

When  using  the  instrument,  the  legs  of  the  tripod  must 
be  set  firmly  into  the  ground,  and  the  bubble  brought  over 
each  pair  of  leveling-screws  in  turn  and  leveled  in  each 
position,  any  necessary  correction  being  made  in  the  adjust- 
ments. 

Care  should  be  taken  to  bring  the  wires  precisely  into 
focus,  and  the  object  distinctly  into  view,  so  that  all  errors 
of  parallax  may  be  avoided.  In  all  instances,  the  wires 
and  object  should  be  brought  into  view  so  perfectly  that 


ENGINEERS  LEVELS  175 

the  cross-wires  will  appear  to  be  fastened  "to  the  surface, 
and  will  remain  in  that  position  however  the  eye  is  moved. 

In  running  levels  it  is  best,  wherever  possible,  that  equal 
fore  and  back  sights  should  be  taken,  to  avoid  any  error 
arising  from  the  curvature  of  the  earth,  and  also  to  correct 
any  errors  of  adjustment  in  the  instrument. 

If  the  socket  of  the  instrument  becomes  so  firmly  set  in 
the  leveling-head  as  to  be  difficult  of  removal,  the  engineer 
should  place  the  palm  of  his  hand  under  the  Y  nuts  at  each 
end  of  the  bar  and  give  a  sudden  upward  blow  to  the  bar, 
taking  care  to  hold  his.  hands  so  as  to  grasp  it  the  moment  it 
is  free. 

If  there  is  any  roughness  in  the  movement  of  the  objective 
slide,  it  may  be  looked  for  in  three  places  : 

1.  Remove  the  four  screws  that  attach  the  pinion  strap 
to   the   telescope.     See   that   the   pinion  turns  freely  in  its 
socket ;  if  it  does  not,  there  is  dirt  in  the  bearing  which  is 
cutting   its   surface.      Remove  the   nut  at   the   end  of    the 
pinion  rod  and  knock  the  pinion  out  of  its  head  with  a  block 
of  wood.     The  scratched  surface  can  be  rubbed  smooth  with 
the  back  of  a  knife  blade.     Put  a  little  tallow  on  the  bearings 
and  replace  the  parts. 

2.  While  the  pinion  is  out  see  that  the  slide  moves  freely 
in  or  out.     If  it  scratches,  rub  it  smooth. 

3.  If  the  pinion  movement  and  slide  are  found  in  good 
order,  the  roughness  may  be  on  the  slide  of  the  slot  opposite 
the  rack,  on  the   edge  which   bears  upon  the  back  of    the, 
pinion  socket.      Rub  this  smooth  and  apply  a  little  tallow. 


17G  ENGINEERS'   LEVELS 

We  now  use  in  the  objective  slides  of  all  our  telescopes, 
as  well  as  in  the  pinion  sockets,  an  anti-friction  bearing 
which,  after  a  trial  of  several  years,  has  proved  to  be  a  com- 
plete preventive  of  the  abrasion  or  fretting  of  the  surfaces 
above  mentioned. 


NO.  378 

15-INCH  Y  LEVEL.     Price  as  shown,  with  tripod,  $90.00 

The  fifteen-inch  Level,  as  shown,  has  the  same  arrange- 
ment of  sockets,  tripod,  etc.,  as  the  larger  levels,  but  has  no 
pinion  movement  to  the  eyepiece.  The  shade  to  the  objective 
is  removable.  The  leveling-head  remains  attached  to  the 
spindle,  and  is  packed  with  it  in  the  box.  The  instrument 
is  somewhat  smaller  and  lighter  than  the  other  sizes. 


ARCHITECTS'  LEVELS  177 

SIZES  The  average  weights  of  the  different  sizes 

AND  WEIGHTS      of  our  Y  Levels,  exclusive  of  the  tripod,  are 
about  as  follows : 

22-inch  telescope,  with  leveling-head 14^  Ibs. 

20-inch        "                       "                13|lbs. 

18-inch        «                       "                13£lbs. 

15-inch        "                       "                Hi  Ibs. 

Architects'  Level,                "                6|  Ibs. 

ARCHITECTS'   LEVEL 


NO.  380 

Price  as  shown,  with  tripod,  $50.00. 

The  figure .  represents  a  level,  introduced  by  us  in  1874, 
which  is  very  largely  used  by  architects,  builders  and  mill- 
wrights, as  well  as  by  engineers  and  surveyors,  in  .the  grading 
of  streets,  sewers  and  drains. 

The  instrument  has  a  telescope  twelve  inches  in  length, 
furnished  with  rings  and  Ys  like  that  of  the  larger  levels  and 
adjusted  in  the  same  manner.  As  now  made,  the  telescope 
can  be  focused  upon  an  object  only  six  and  one-half  feet  from 
the  center  of  the  instrument. 


178 


ARCHITECTS'  LEVELS 


The  leveling -head  has  the  screws  and  clamp  to  the  spindle, 
but  no  tangent  movement.  It  has  also  a  horizontal  circle 
three  inches  in  diameter,  fitted  to  the  upper  end  of  the  socket 
and  turning  readily  upon  it.  The  circle  is  graduated  to  de- 
grees, figured  from  0  to  90  each  way,  and  is  read  to  five 
minutes  by  a  vernier  which  is  fixed  to  the  spindle. 

The  telescope  is  directed  to  any  object  by  hand,  the  spin- 
dle turning  readily  in  its  socket ;  but  it  can  be  clamped  in 
any  position  by  the  clamp  screw  shqwn  under  the  circle. 

The  instrument  is  placed  either  upon  a  light  tripod  as 
shown,  or  on  a  small  triangular  plate  called  a  trivet,  having 
three  sharp  steel  points  by  which  it  is  firmly  set  upon  any 
surface.  Both  tripod  arid  trivet  are  furnished  with  the  level. 
A  short  piece  of  tube  called  a  shade  is  also  supplied,  to 
put  over  the  objective  to  protect  it  from  the  glare  of  the 
sun. 

We  add  to  the  Architects'  Level,  when  desired,  a  clamp 


- 
f-V 


NO.  381 

Price  as  shown,  with  clamp  and  tangent,  $65.00. 


ARCHITECTS1  LEVELS  179 

and  tangent  movement,  which  allows  the  instrument  to  be 
clamped  more  securely,  and  a  movement  in  a  horizontal  plane 
to  be  made  more  accurately.  See  page  178. 

The  adjustments  of  the  Architects'  Level 

ADJUSTMENTS 

are  made  exactly  as  described  in  the  account 
of  the  larger  levels.  They  are  not  liable  to  derangement, 
and  will  ordinarily  require  but  little  attention. 

TO   USE    THE  ARCHITECTS'  LEVEL 

The  instrument  should  be  set  firmly  upon  the  tripod  or 
trivet,  in  a  position  as  nearly  level  as  practicable,  the  tele- 
scope placed  over  either  pair  of  leveling-screws,  and  the 
bubble  brought  into  the  middle  by  turning  the  opposite 
screws  either  in  or  out  as  may  be  needed,  and  both  screws 
brought  to  a  bearing  in  the  little  cups  underneath.  Having 
brought  the  bubble  into  the  middle  of  the  vial,  turn  the 
telescope  over  the  other  pair  of  screws  and  repeat  the 
operation. 

The  instrument  having  been  carefully  leveled,  focus  the 
eyepiece  and  objective  upon  the  object  as  before  described, 
and  the  horizontal  cross-wire  will  give  any  number  of  points 
required,  which  will  all  be  in  the  same  level  plane. 

A  board  held  erect  will  answer  as  a  rod,  and  a  pencil  line 
drawn  across  it  at  the  place  cut  by  the  horizontal  wire  will 
give  the  height  of  the  starting-point.  Any  different  points 
on  the  rod,  either  above  or  below  that  indicated  by  the  cross- 
wire,  will  show  the  difference  in  height  of  the  various  points 
observed,  as  compared  with  the  starting-point. 

In  laying  off  angles  with  the  Architects'  Level,  the 
LAYING  OFF  bubbles  should  first  be  brought  into  the  mid- 
ANGLES  die  as  before  described,  and  the  vertical  cross- 
wire  made  to  cut  the  object  or  line  from  which  the  angle  is 


180 


ARCHITECTS'  LEVELS 


to  be  taken.  Then,  the  spindle  being  clamped  by  the  milled- 
head  screw  under  the  circle,  the  circle  is  turned  around  by 
hand  until  the  zero  lines  of  both  circle  and  vernier  are  made 
to  coincide.  Loosen  the  clamp  screw  and  turn  the  telescope 
to  the  point  desired,  and  the  angle  between  the  two  points 
will  be  read  off  on  the  circle. 

By  the  use  of  the  vernier  angles  can  be  read  on  the  circle 
to  five  minutes,  but  ordinarily  only  even  angles  will  be  taken 
and  only  the  middle  line  of  the  vernier  used. 

The  point  underneath  the  center  of  the  instrument  is  indi- 
cated by  the  point  of  the  plummet  suspended  from  the  tripod. 

A.....E  In    many  cases,    after    the    walls    of   a 

building  have  been  carried  up  to  a  consid- 
erable height,  it  becomes  difficult  to  set  up 
the   tripod,  and  in   this   case  the   level    is 
screwed  upon  the  trivet,  which  can  be  set 
upon  the  wall  or  a  piece  of  board  tacked 
to  the  building,  or  indeed  upon  any  surface 
nearly  level  and  not  less  than 
six  inches  square. 

To  illustrate  the  value  of 
this  instrument  in  laying  out 
the  sites  of  buildings,  suppose 
it  is  desired  to  erect  a  building,  C  D,  at  right  angles  with  a 
building,  A  B,  and  at  a  given  distance  from  its  front. 

First  set  up  the  level  at  E,  and  carefully  center  the  bubble, 
the  point  of  the  plummet  below  indicating  the  required  dis- 
tance of  the  side  of  the  new  building  from  the  front,  A  B. 
Measure  the  same  distance  at  the  other  corner  of  A  B,  and, 
having  erected  the  rod,  sight  upon  it  with  the  telescope  and 
clamp  to  the  spindle. 

Now  carry  the  rod  the  required  distance  from  B,  and 


ARCHITECTS'  LEVELS  181 

move  it  from  side  to  side  until  it  is  again  in  line  with  the 
telescope,  as  at  C. 

Remove  the  instrument,  and  having  carefully  set  it  over 
the  point  C,  by  the  plummet,  and  brought  the  bubble  into 
the  middle  as  before,  set  the  telescope  again  upon  the  rod 
place  at  E  or  F,  and  clamp  to  the  spindle.  Bring  the  zeros 
of  the  circle  and  vernier  to  coincide,  unclamp,  and  turn  the 
vernier  to  ninety  degrees ;  this  will  give  a  point,  D,  at  any 
required  distance  from  C,  and  C  D  will  be  the  side  of  the 
proposed  building.  The  side,  C  G,  is  determined  by  turn- 
ing the  telescope  around  until  the  vernier  is  in  line  with  the 
other  zero  of  the  circle,  and  thus  the  corner,  C,  and  the  two 
sides,  C  D  and  C  G,  are  at  once  set  off,  and  the  remaining 
corner,  H,  easily  ascertained  by  making  D  H  and  G  H  equal 
to  C  G  and  C  D  respectively. 

Other  uses  of  the  level,  as  the  setting  of  floor  timbers, 
of  window-  and  door-sills  and  the  leveling  of  floors,  will 
readily  occur  to  one  who  has  been  engaged  in  building.  To 
the  millwright  such  a  level  is  almost  indispensable  in  the 
aligning  and  leveling  of  shafting,  in  ascertaining  the  fall  of 
water  obtainable  and  in  determining  the  overflow  of  land  by 
a  mill  pond.  The  farmer  will  find  it  of  value  in  locating 
and  laying  out  drains,  ascertaining  the  height  of  springs  and 
similar  work. 

This  level  has  become  widely  known,  and  its  cheapness, 
simplicity  and  excellence  have  created  a  great  demand  for  it. 


182  DRAINAGE  LEVEL 


NO. 387 

Price  as  shown,  $25.00 

DRAINAGE  LEVEL.  (New  Pattern.) 
No.  387  represents  a  level  combining  great  simplicity  and 
compactness  with  real  efficiency,  at  a  very  moderate  cost. 
The  telescope  is  about  nine  inches  long  and  is  made  especially 
for  this  instrument,  being  achromatic,  of  low  but  sufficient 
power,  and  giving  good  light  and  definition.  The  cross-wires 
are  fixed  in  the  eyepiece  so  that  they  are  not  easily  disturbed. 
The  level,  telescope  and  socket  are  enclosed  in  a  strong  out- 
side case  of  brass,  about  seven  and  one -half  inches  long,  two 
and  one-quarter  inches  wide  and  one  and  one-half  inches 
high. 

The  ends  of  the  case  are  thickened  and  made  parallel 
each  to  each,  on  the  upper  and  under  sides. 

A  ball  attachment,  by  which  the  instrument  is  made  ap- 
proximately level,  screws  into  a  spindle  which  is  within  the 
case.  The  precise  leveling  is  done  by  the  leveling-screws,  as 
shown.  When  desired,  the  leveling-head  can  be  dispensed 
with,  and  the  instrument  leveled  by  the  ball  alone. 


DRAINAGE  LEVEL  183 

A  compass  with  three-inch  needle  is  added  to  the  Drainage 
Level,  when  desired.  This  is  fitted  to  the  upper  surface  of  the 
case  and  can  be  removed  at  pleasure,  and  while  it  does  rrot 
interfere  in  any  way  with  the  reading  of  the  level-vial,  it  fur- 
nishes a  ready  means  of  determining  the  bearing  of  lines  or 
of  measuring  angles  by  the  needle. 


This  level   is  adjusted  almost  as  simply  as  an   ordinary 

masons'   or  builders'  level,  in  the  following  manner:     The 

spirit-level,  by  reversing  from  end  to  end 

ADJUSTMENTS  *f  ,     . 

on  the  lower  faces  of  the  case,  and  making 
necessary  corrections  by  the  screws  at  the  eyepiece  end,  marked 
"  L"  on  opposite  faces  and  in  line  with  the  level-tube;  the 
telescope,  by  applying  the  opposite  faces  alternately  to  the  same 
surface,  and  bringing  the  telescope  cross-wires  by  two  screws 
marked  "  T,"  one  on  each  face,  so  as  to  cut  the  same  point  in 
both  positions  of  the  case.  A  small  block  of  wood,  having  a 
screw-thread  that  fits  the  top  of  the  ball  attachment,  is  furnished 
with  the  instrument,  for  use  in  making  the  above  adjustments. 
When  the  ball  is  screwed  firmly  to  the  spindle  and  the 
instrument  leveled,  it  should  remain  level  when  reversed  upon 
its  spindle  in  any  direction.  If  it  does  not,  correct  the  error 
by  the  two  screws  on  the  opposite  sides  of  the  case,  marked 
"S."  Should  the  cross -wires  be  indistinct  or  out  of  focus, 
unscrew  the  cap  of  the  eyepiece  and  turn  the  setting  of  the 
lens  around  in  either  direction  until  the  wires  are  clearly  seen, 
when  the  cover  may  be  replaced. 


184  DRAINAGE  LEVEL 

Of  course,  these  adjustments  are  always  made  by  the 
maker,  -and  are  not  liable  to  derangement  in  the  careful  use 
of  the  level. 

To  clamp  the  instrument  on  the  spindle,  turn  the  small 
milled-head  screw  at  the  eyepiece  end.  To  screw  the  ball 
attachment  to  the  spindle,  press  in  the  spring  catch  at  the 
bottom  of  the  case,  and  the  ball  can  then  be  easily  screwed  in. 

The  advantages  of  this  level  in  the  work  of  the  farmer, 
manufacturer  and  builder  will  be  apparent.  Drains  can  be 
located  and  leveled,  the  height  of  springs  ascertained,  and  the 
accurate  level  of  lines  of  shafting,  floor  timbers  and  sills  be 
determined. 

The  Architects'  leveling-rod,  hereafter  described,  is  in- 
tended for  use  with  this  instrument,  when  desired. 

PRICES 

No. 

385  Drainage-Level,  with  staff  mountings ... .      $15.00 

386  "       with  plain  tripod 20.00 

387  "       with  tripod  and  leveling-screws 25.00 

388  "             "       with  tripod  and  leveling-screws,  and  with 
compass  and  clamp-screws 30.00 


TRIPODS 

LEATHER  CASES  AND  POUCHES 

LEVELING-RODS 

RANGING  POLES 

ROD  LEVEL 

PLANE-TABLES 

ALIDADES 

BATSON  SKETCHING-CASE 

CURRENT  METERS 

HAND  LEVELS 

CHAINS 

TAPES 


TRIPODS 


T  N  THE  tripods  of  all  our  instruments,  the  upper  part  of  the 
leg  is  flattened  and  slotted  to  fit  closely  on  each  side  of  a 
strong  tenon  projecting  from  the  under  side  of  the  tripod 
head,  to  which  it  is  firmly  held  by  a  strong  brass  bolt,  with 
large  head  and  thumb-nut  on  opposite  sides  of  the  leg.  The 
tripod  head  is  of  the  best  bell  metal,  the  tenons  and  upper 
part  being  cast  in  one  piece  and  firmly  braced  together.  The 
legs  are  round,  and  taper  in  each  direction  toward  the  head 
and  point.  The  point  or  shoe  is  a  tapering  brass  ferrule, 
having  an  iron  end.  It  is  cemented  and  firmly  riveted  to  the 
wood. 

The  legs  of  all  our  tripods  are  made  of  straight -grained 
hardwood,  and  are  about  four  feet  eight  inches  long  from 
head  to  point. 

We  make  four  sizes  of  tripods  with  solid  legs,  as  follows : 
The  heavy  tripod,-  No.  400,  has  a  metal  head  four  and  one- 
quarter  inches  in  diameter,  with  legs  one  and  three-eighths 
inches  in  diameter  at  the  top,  one  and  three-quarters  at  the 
swell,  and  one  and  one-eighth  near  the  point.  This  is  used 
with  the  Engineers'  Transit  and  with  the  larger  Y  Levels. 

The  medium -size  tripod  has  a  head  the  same  diameter  as 
the  former,  and  legs  which  are  one  and  one-eighth  inches  in 
diameter  at  the  top,  one  and  five-eighths  at  the  swell,  and  one 
and  one-sixteenth  near  the  point.  This  tripod  is  used  with 
the  Surveyors'  Transit,  the  light  Engineers'  Transit  and  the 
fifteen -inch  Level. 

The  compass  tripod,  No.  415,  has  a  head  about  three 
inches  in  diameter,  and  legs  which  are  about  one^inch  in 

186  > 


TRIPODS 


187 


diameter  at  the  top,  one  and  three-eighths  at  the  swell,  and 
seven -eighths  near  the  point.  This  tripod  is  used  with  the 
various  compasses  and  with  the  Vernier  Transit  Compass. 

PLAIN   TRIPODS 


188 


TRIPODS 


The  pocket  compass  tripod  is  the  same  pattern  as  No.  415, 
but  has  smaller  head  and  legs.  The  legs  are  nearly  three- 
quarters  of  an  inch  in  diameter  at  the  top  and  bottom,  and 
one  and  one -eighth  at  the  swell. 

SPLIT-LEG    TRIPOD 

The  improved  split- 
leg  tripod  is  shown  in  the 
engraving.  The  form  is 
shown  in  section  at  A  B. 

The  legs  are  of 
straight  -  grained  h  a  r  d- 
wood,  and  by  the  new 
form  stiffness  and  strength 
are  gained,  with  reduced 
weight  and  greater  ease 
in  carrying.  We  are  con- 
fident that  engineers  will 
regard  these  changes  as 
decided  improvements. 

We  make  several  sizes 
of  this  tripod,  for  use 
with  transits,  levels  and 
compasses. 


IMOS.  405  AND  435 


TRIPODS  189 


EXTENSION  TRIPOD 

In  No.  410  is  shown 
a  decided  improvement 
on  the  old  pattern  of  ex- 
tension tripod,  which  has 
proved  so  popular.  The 
new  tripod  is  lighter, 
stronger  and  more  rigid 
than  the  old  pattern. 
The  form  is  shown  in 
section  at  A  B. 

The  new  tripod  can 
be  carried  more  easily 
than  the  old,  and  the 
shape  of  the  side  pieces 
allows  the  middle  piece 
to  be  clamped  firmly  with 
the  two  bands  and  screws, 
while  slight  changes  in 
length  can  be  made  by 
twisting  the  middle  piece 
up  or  down.  The  legs 
are  clamped  to  the  tripod 
head  with  thumb -nuts. 
We  make  several  sizes  of  extension  tripods.  The  large 
size  is  used  with  the  large  transits  and  levels,  and  the  medium 
size  with  the  Mountain  Transit.  A  smaller  size  is  used  with 
the  smaller  transits,  Architects'  Levels  and  large  compasses, 
and  the  smallest  size  is  used  with  the  pocket  compasses. 

For  prices  of  plain,  split-leg  and  extension  tripods,  see  pages  280  and 
281  of  the  Price  List. 


19.0  LEATHER    CASES 

LEATHER  CASES  AND  POUCHES 


.NO.  490 

The  pouch  shown  in  the  cut  furnishes  a  very  convenient 
method  for  carrying  small  pocket  compasses  without  tele- 
scopes, as  Nos.  288  to  350. 

These  pouches  are  strongly  made,  furnished  with  adjust- 
able sling  strap,  and  so  arranged  as  to  hold  the  compass  and 
its  mountings  firmly  and  protect  them  from  injury  in  trans- 
portation. The  wooden  box  in  which  the  small  compasses 
are  packed  is  omitted  when  the  leather  pouch  is  used.  The 
leather  cases,  however,  are  fitted  to  hold  the  wooden  box 
containing  the  instrument,  and  are  used  with  any  transit, 
level,  compass,  or  pocket  compass. 

We  have  the  best  facilities  for  making  all  kinds,  of  leather 
work  to  order,  and  can  promptly  furnish  anything  in  the  line 
of  cases  or  pouches  for  surveying  instruments.  We  also  make 
to  order  canvas  cases  for  carrying  tripods  and  levelihg-rods. 

For  prices  of  leather  cases  and  pouches,  see  page  282  of  the  Price  List. 


LEVELING-RODS 


THE  following  pages  we  give  cuts  and  descriptions 
of  the  leveling -rods  commonly  used  by  American  engi- 
neers and  surveyors,  which  are  manufactured  by  us  in  large 
numbers  and  kept  constantly  in  stock. 

Our  facilities  for  the  manufacture  of  leveling -rods  have 
for  many  years  surpassed  those  of  all  other  makers.  The 
greatest  care  is  exercised  in  the  selection,  preparation  and 
seasoning  of  the  wood,  and  special  appliances  and  machinery 
for  the  work  have  been  constructed  at  great  cost.  Many 
improvements  in  design  and  in  the  construction  of  parts  have 
been  made,  with  a  view  to  producing  the  best  results  obtain- 
able, and  in  point  of  finish  and  accuracy  our  rods  are  unex- 
celled. 

For  many  years  we  have  made  to  order  special  rods  to 
designs  furnished,  which  have  been  used  in 

SPECIAL   RODS  .         .  .  ,  .    _ 

the  most  critical  work  with  perfect  satisfac- 
tion.    We  are  prepared  to  make  rods  of  any  design  to  order. 

PHILADELPHIA   ROD 

No.  500 

This  rod  is  made  in  two  parts,  each  about  three-quarters 
of  an  inch  thick  by  one  and  one -half  inches  wide  and  seven 
and  three-tenths  feet  long,  the  parts  connected  by  two  metal 
sleeves,  the  upper  one  of  which  has  a  clamp  screw  for  fasten- 
ing the  two  parts  together  when  the  rod  is  extended  for  a 
higher  reading  than  seven  feet. 

Both  sides  of  the  back  strip  and  one  side  of  the  front  are 
recessed  one-sixteenth  of  an  inch  below  the  edges.  These 
surfaces  are  painted  white,  graduated  into  feet,  tenths  and 

191 


LEVELING-RODS 


3-= 


R 


hundredths  of  a  foot,  and  the  feet  and  tenths 
figured.  The  graduations  and  figures  are 
slightly  impressed  on  the  recessed  surfaces,  thus 
increasing  their  durability. 

The  edges  of  the  rod  and  the  corners  of 
the  brass  mountings  are  rounded,  for  ease  in 
handling. 

The  front  piece  reads  from  the  bottom 
upward  to  seven  feet,  the  foot  figures  being  red 
and  the  tenth  figures  black.  When  the  rod  is 
extended  to  full  length  the  front  surface  of  the 
rear  half  reads  from  seven  to  thirteen  feet,  and 
the  whole  front  of  the  rod  is  figured  continu- 
ously and  becomes  a  self -reading  rod,  thirteen 
feet  long,  reading  to  hundredths  of  a  foot. 

The  back  surface  of  the  rear  half  is  figured 
from  seven  to  thirteen  feet,  reading  from  the 
top  down.  It  has  a  vernier  scale  by  which  the 
rod  is  read  to  thousandths  of  a  foot  as  it  is  ex- 
tended. The  target  is  round,  made  of  brass 
raised  on  the  perimeter  to  increase  its  strength, 
and  is  painted  in  white  and  red  quadrants.  It 
has  also  a  vernier  scale  on  its  chamfered  edge, 
reading  to  thousandths  of  a  foot. 

When  a  level  of  less  than  seven  feet  is 
desired,  the  target  is  moved  up  or  down  the 
front  surface,  the  rod  being  closed  and  clamped ; 
but  when  a  greater  height  is  required  the  target 
is  fixed  at  seven  feet  and  the  rear  half  extended, 
the  vernier  scale  on  the  back  giving  the  read- 
ings like  those  of  the  target  to  thousandths  of 
a  foot. 


LEVELING-RODS 


PHILADELPHIA   ROD 


193 


In  three  parts.     No.  501 

To  provide  a  rod  of  the  same  general 
design  and  use  as  the  Philadelphia  rod,  but 
capable  of  being  closed  to  shorter  length,  we 
have  recently  introduced  the  Philadelphia  rod 
in  three  parts.  This  rod  is  five  and  three- 
tenths  feet  long  when  closed,  and  when 
extended  reads  to  thirteen  feet. 

In  reading  above  five  feet  the  rear  part  is 
extended,  the  readings  being  made  on  the 
graduated  edges  of  the  rod  by  vernier  to 
thousandths  of  a  foot. 

When  fully  extended  the  front  surface  be- 
comes a  self-reading  rod  to  thirteen  feet,  the 
graduations  being  to  hundredths  of  a  foot. 

On  account  of  ease  in  transportation,  as 
well  as  the  general  character  and  excellence 
of  this  rod,  we  believe  it  will  be  approved  by 
those  who  use  it. 


194 


LEVELING-RODS 


BOSTON  ROD 
No.  503 

This  rod  is  formed  of  two  pieces,  each  about 
six  feet  long,  sliding  easily  by  each  other  in 
either  direction. 

One  side  is  furnished'  with  a  clamping  piece 
and  screw,  with  a  small  vernier  at  each  end ;  the 
other  or  front  piece  carries  the  target,  and  has 
on  each  side  an  inlaid  strip  upon  which  gradu- 
ations of  feet,  tenths  and  hundredths  are  marked 
and  figured. 

The  target  is  a  disk  of  brass  raised  on  its 
perimeter,  fastened  on  the  front  half,  and  painted 
red  and  white,  its  middle  line  being  just  three- 
tenths  of  a  foot  from  the  end  of  the  rod. 

Each  tenth  graduation  is  figured  decimally  in 
three  figures,  or  to  hundredths  of  a  foot,  and  by 
the  verniers  is  read  to  thousandths. 

The  target  being  fixed,  when  any  height  is 
taken  above  six  feet  the  rod  is  changed  end  for 
end,  and  the  graduations  read  by  the  other 
vernier,  the  height  to  which  the  rod  can  be  ex- 
tended being  a  little  over  eleven  feet. 

This  rod  is  very  convenient  on  account  of 
its  lightness,  but  the  parts  are  too  frail  to  with- 
stand the  rough  usage  of  this  country,  and 
American  engineers  generally  prefer  other  rods 
which  are  heavier  and  more  substantial. 


LEVELING-RODS  195 

TROY  ROD 
No.  "504 

The  cut  represents  another  form  of  the 
sliding  leveling  -  rod,  called  the  Troy  rod. 
This  is  a  self-reading  rod  up  to  six  feet,  or  it 
can  be  read  by  a  vernier  on  the  rear  piece  to 
thousandths  of  a  foot,  as  usual.. 

It  has  two  targets  as  shown,  both  fastened 
to  the  front  half  of  the  rod,  the  lower  one  having 
its  middle  line  just  three-tenths  of  a  foot  above 

|    the   end,  and  the  other  target   exactly  six  feet 

*  above  the  lower. 

V  .    « 

There    is  a   clamping   piece  with  screw  on 
.    the  back  of  the  rod,   below  the  upper  target, 
g    by  which  the   two   parts  are  clamped  together 
>    when  desired. 

Q 

The  face  of  the  front  piece  is  recessed  like 
.   that    of    the    Philadelphia    rod,    painted  white, 
>   graduated  to  feet  and  hundredths,  and  figured 
^   as  represented. 

z  The  side  of  the  front  half  is  graduated  to 
feet  and  hundredths,  read  by  a  vernier  on  the 
top  of  the  rear  half  to  thousandths,  and  figured 
from  the  top  downward,  beginning  with  three- 
tenths,  that  being  the  height  of  the  middle  line 
of  the  lower  target. 

When  a  level  of  less  than  six  feet  is  taken, 
on  the  rod  the  observation  is  made  by  the 
lower  target,  and  the  reading  is  direct  as  given 
on  the  side ;  but  when  a  greater  height  is  taken 
the  upper  target  is  sighted  upon,  and  six  feet 


196  LE  VELING-RODS 

added  to  the  reading  on  the  side,  a  reading  up 
to  twelve  feet  being  thus  readily  obtained. 

NEW    YORK  ROD 
No.  505 

This  rod  is  made  in  two  parts,  the  pieces 
sliding  one  from  the  other,  the  same  end  being 
always  held  on  the  ground  and  the  graduations 
starting  from  that  point. 

The  graduations  are  made  to  tenths  and  hun- 
dredths  of  a  foot,  the  tenth  figures  being  black, 
and  the  feet  marked  with  a  large  red  figure. 

The  front  surface,  on  which  the  target  moves, 
reads  to  six  and  one-half  feet  on  the  two-part 
rods.  When  a  greater  height  is  required,  the 
horizontal  line  of  the  target  is  fixed  at  the  highest 
graduation,  and  the  upper  half  of  the  rod  carry- 
ing the  target  is  moved  out  of  the  lower,  the 
reading  being  now  obtained  by  a  vernier  on  the 
graduated  side,  up  to  an  elevation  of  twelve  feet. 

The  target  is  round,  made  of  brass  with  a 
raised  rim  to  strengthen  it  and  to  protect  the 
paint  from  defacement.  It  is  arranged  with  an 
improved  clamp,  which  can  be  so  adjusted  as  to 
regulate  the  friction  on  the  rod,  allowing  the  tar- 
get to  be  easily  moved  up  and  down  or  to  be 
clamped  by  a  slight  turn  of  the  binding-screw. 

The  face  of  the  target  is  divided  into  quad- 
rants by  horizontal  and  vertical  diameters,  the 


1: 


LEVELING-RODS 


197 


quadrants  being  painted  alternately  white  and 
red,  or  sometimes  white  and  black. 

The  opening  in  the  face  of  the  target  is 
nearly  two-tenths  of  a  foot  long,  so  that  in  any 
position  a  figure  noting  a  tenth  of  a  foot  can 
be  seen  on  the  surface  of  the  rod. 

The  right  edge  of  the  opening  is  chamfered, 
and  graduated  into  ten  equal  spaces  correspond- 
ing to  nine  hundredths  on  the  rod.  The 
graduations  start  from  the  horizontal  line  which 
separates  the  colors  of  the  face. 

The  vernier,  like  that  on  the  side  of  the  rod, 
reads  to  thousandths  of  a  foot.  The  rod  is 
fitted  with  the  improved  clamp. 


NEW    YORK  ROD 
In  three  parts.     No.  507 

In  this  rod,  as  shown,  a  third  piece  is  added, 
giving  a  rod  of  greater  length,  and  at  the  same 
time  making  it  more  compact  and  portable. 
The  graduations,  verniers  and  readings  are  the 
same  as  those  of  the  rod  in  two  parts. 

The  three -part  rod  allows  a  reading  of 
twelve  and  one-half  feet,  and  when  closed  is 
five  feet  long. 


MINING  RODS 
Nos.  502A  and  509 

Both  the  Philadelphia  rod  and  the  New 
York  rod  in  two  parts  are  made  in  lengths 
suitable  for  use  in  underground  work,  reading 


LEVELING-RODS 


when  closed  to  three  and  three-tenths  feet,  and 
sliding  to  five  feet  when  extended. 

ARCHITECTS'   ROD 
Nos.  510  and  511 

This  is  a  very  light  and  simple  sliding  rod  in 
two  equal  parts,  each  seven -eighths  of  an  inch 
square,  and  when  closed  the  rod  is  about  five  feet 
six  inches  long. 

As  shown,  the  front  half  is  graduated  on 
two  sides  to  feet,  tenths  and  hundredths,  reading 
by  verniers  on  the  target  and  side  to  thousandths 
of  a  foot. 

The  target  is  similar  to  those  of  the  rods 
already  described,  and  moves  on  the  closed  rod 
when  levels  of  less  than  five  and  four-tenths  feet 
are  to  be  taken. 

When  a  greater  height  is  needed,  the  target 
is  fixed  at  the  highest  graduation,  the  front  half 
carried  above  the  rear  part  and  clamped  by  the 
clamp  screw  at  any  point  desired,  and  the  height 
up  to  ten  feet  read  off  by  the  vernier  on  the 
lower  half. 

This  rod  is  adapted  for  use  with  any  level, 
and  is  so  light  and  efficient  that  it  has  been 
received  with  favor.  It  is,  however,  generally 
used  with  the  Architects'  and  Drainage  Levels. 
When  it  is  designed  for  architects'  use  the  gradu- 
ations are  in  feet,  inches  and  sixteenths,  and  no 
verniers  are  required. 


LEVELING-RODS  199 

MACHINISTS'   ROD 
No.  512 

The  Machinists'  rod  is  in  one  piece 
with  a  cross-section  about  seven -eighths 
of  an  inch  square  and  a  length  of  six 
and  one-half  feet,  and  is  graduated  on 
one  face  to  feet,  inches  and  sixteenths. 
Attached  to  one  end  of  the  rod  with  a 
swivel  is  a  large  hook  by  which  the  rod 
§  may  be  hung  from  a  shaft. 

The  target  is  painted  red  with  broad 
•c  white  lines  crossing  the  center,  and  is 
.  fitted  with  candle -holder.  This  rod  is 
o  designed  especially  for  use  in  leveling 
^  shafting  in  factories,  and,  used  with  the 
w  Architects'  Level,  will  be  found  of  great 

«    service. 

o 

S         TELEMETER  OR  STADIA  ROD 

3J  No.  513 

w          This  rod  is  formed  of  two  pieces  of 

o  pine,  each  two  and  one-half  inches  in 
width  and  six  feet  long.  The  inner  sur- 
faces of  the  rod  -are  recessed  and  painted 
white,  with  graduations  in  black  to  feet, 
tenths  and  hundredths,  the  feet  figured 
in  red  and  the  tenths  in  black.  The  two 
pieces  are  connected  by  strong  brass 
hinges  and  are  folded*  in  transportation. 
When  in  use  they  are  opened,  laid  flat « 
and  held  firmly  in  line  by  a  strong  clip 
on  the  back  of  the  rod.  The  rod  tapers 


200 


LEVELING-RODS 


toward  the  top  from  a  thickness  at  the  bottom  of 
one  and  one -eighth  inches. 

This  is  a  self-reading  rod,  and  is  often  used  in 
connection  with  the  stadia  to  ascertain  distances 
by  simple  observation,  in  the  same  manner 
as  the  Philadelphia  rod. 


TELESCOPIC  ROD 

No.  515 

This  rod  is  so  made  that  the  two 
smaller  upper  parts  slide  out  of  a  larger 
and  lower  part  which  answers  as  a  case. 
When  closed,  the  rod  is  five  feet  long, 
and  it  extends  to  fourteen  feet.  It  is 
graduated  on  a  recessed  face  to  feet, 
tenths  and  hundredths,  the  graduations 
being  painted  and  figured  like  those  of 
the  Philadelphia  and  Telemeter  rods. 


CROSS-SECTION  ROD 

No.  516 

This  rod  is  made  of  well -seasoned 
pine,  and  is  ten  feet  long  and  one  and 
one-half  inches  square  at  the  ends.  It 
is  about  four  inches  thick  at  the  middle, 
where  there  is  an  opening  for  the  hand 
as  shown.  Both  sides  are  graduated  on 
a  recessed  white  surface,  the  graduations 
being  painted  black  like  those  of  a 
leveling-rod,  and  .figured  from  the  same 
end  of  the  rod.  There  is  also  an 
adjustable  spirit-level  at  each  end,  one 
pf  which  is  shown  in  the  cut. 


LEVELING-RODS 


201 


PLAIN  LEVELING-ROD 

No.  518A 

A  very  good  self -reading  rod 
is  made  of  seasoned  white  pine, 
recessed  and  graduated  on  one 
face  like  the  Philadelphia  rod. 
A  rib  at  the  back,  extending 
through  the  length  of  the  rod, 
gives  great  rigidity,  while  it 
does  not  materially  increase  the 
weight.  This  rod  is  commonly 
made  ten  and  twelve  feet  long, 
but  can  be  made  longer  if  de- 
sired, at  an  additonal  cost  of 
about  fifty  cents  per  foot.  These 
rods  are  also  made  with  a  hinge 
joint  at  the  middle.  See  page 
284. 

PLAIN  LEVELING-ROD 

In  four  parts,  No.  524A 
This  is  a  simple  form  of  self- 
reading  rod  in  four  parts,  very 
light  and  compact,  capable  of 
extension  to  eleven  and  two- 
tenths  feet,  and  reading  to  hun- 
dredths  of  a  foot.  This  same 
form  of  rod  is  also  made  in  two 
parts,  extending  to  ten,  twelve 
or  fourteen  feet.  See  Nos. 
522A,  B  and  C, 


202  LEVELING-RODS  AND   POLES 

METRIC  RODS 

Besides  the  usual  graduation  of  leveling-rods  into 
feet  and  parts  of  a  foot,  we  graduate  them,  when 
desired,  into  meters,  decimeters  and  centimeters. 
The  scales  on  the  targets  and  sides  of  the  rods  read 
the  centimeters  to  millimeters  on  all  except  the  tele- 
meter, telescopic  and  plain  rods,  which  have  no  targets 
and  are  read  only  to  centimeters.  The  New  York, 
Troy,  Boston  and  Architects'  metric  rods  are  graduated, 
when  desired,  to  read  by  vernier  to  one -tenth  of  a 
millimeter. 

FLEXIBLE  OR  POCKET  LEVELING-RODS 
Nos.  525A  to  528 

A  convenient  form  of  self-reading  rod,  where  only 
approximate  results  are  essential,  is  the  flexible  or 
pocket  leveling-rod,  as  shown  on  page  284  of  the  Price 
List. 

This  rod  is  .made  of  specially  prepared  canvas, 
graduated  on  its  painted  surface  to  feet,  tenths  and 
hundredths,  or  to  special  design,  and  when  not  in  use 
it  can  be  rolled  up  and  carried  in  a  case  or  in  the 
pocket.  In  use  it  is  fastened  to  a  board  with  thumb- 
tacks. 

LEVELING-POLE 

The  leveling-pole,  shown  in  No.  530,  is  a  combi- 
nation of  a  plain  self -reading  rod  and  a  flag-pole.  It 
is  made  with  flat  face,  front  and  rear,  and  rounded 
sides.  One  face  is  graduated  to  feet  and  hundredths 
of  a  foot,  while  the  other  face  and  sides  are  graduated 
53O  to  feet  only  and  are  painted  red  and  white  alternately. 


FLAG  STAFFS 


203 


The  pole  is  made  seven  and  nine  feet  long, 
the  graduated  faces  reading  to  six  and  eight  feet 
respectively,  and  when  used  as  a  rod  is  read  as 
shown  in  the  cut.  See  page  285. 

WOOD  AND  IRON  FLAGSTAFFS 

We  make  three  sizes  of  the  common  wood  flag- 
staffs,  or  ranging-poles.  They  are  octagonal  in 
form,  tapering  from  the  bottom  to  the  top,  are  six, 
eight  and  ten  feet  long,  and  have  steel  shoes. 
See  cut,  No.  534. 

We  also  make  a  ranging-pole  of  an  iron  tube, 
eleven -sixteenths  of  an  inch  in  diameter,  hung  in 
gimbals  so  that  it  can  be  readily  set  over  a  given 
point.  See  cut,  No.  539.  Similar  iron  poles  are 
made  without  gimbals,  six,  eight  and  ten  feet  long. 

These  staffs  are  graduated  to  feet,  and  painted 
alternately  red  and  white.  When  desired  they  are 
also  graduated  metrically,  five  spaces  to  each 
meter. 

JOINTED  RANGING-POLE 
Nos.  537A  to  538B 

For  use  where  compactness  is  a  requisite,  we 
make  a  ranging-pole  having  one  or  more  protected 
screw-joints.  This  pole  is  about  one  inch  in  diam- 
eter, and  is  furnished,  if  desired,  with  a  heavy 
canvas  case  to  contain  the  several  parts,  and  to 
protect  them  from  injury  in  transportation.  See 
page  285  of  the  Price  List. 


NO.      NO. 
534     539 


204  ROD  LEVEL 

ROD  LEVEL 


NO.  545.     ROD  LEVEL 
Price,  $3.00. 

ROD  LEVEL  AS  APPLIED  TO  A  ROD 

No.  545  represent?  a  level  for  the  accurate  plumbing  of 
leveling-rods  and  ranging-poles.  The  figures  show  it  when 
folded  for  carrying,  and  also  as  attached  to  a  rod. 

It  is  held  in  place  by  the  hand,  or  it  may  be  secured  by 
a  string  or  rubber  band  slipped  over  hooks  attached  to  each 
plate  of  the  level.  Its  convenience  and  value  have  com- 
mended it  to  general  favor. 

CIRCULAR  ROD  LEVEL 

We  also  make  a  rod  level  with  circular  level-vial,  folding 
against  the  rod  when  not  in  use.  This  level  is  to  be  attached 
to  the  rod,  and  hence  cannot  be  used  where  there  is  a  target 
or  clamp  band  to  slide  past  it.  It  is  very  serviceable  on  self- 
reading  and  stadia  rods.  See  No.  546  of  the  Price  List. 

For  prices  of  leveling-rods,    flagstaff's,  jointed   ranging-poles  and   rod 
levels,  see  pages  283  to  286  of  the  Price  List. 


PLANE-TABLE 


recognized  utility  of  the  Plane-Table  for  topographical 
and  map  drawing  is  bringing  it  into  use  in  this  country, 
and  to  meet  the  demand  for  instruments  of  moderate  cost  and 
real  efficiency  we  have  introduced  several  patterns. 


NO.  553  PRICE 
Plane-Table,  board  30  x  24  inches,  mounted  on  large  tripod, 
with    leveling-socket   and  clamp,   plumbing-arm,   plum- 
met and  clamps  for  paper • $45.00 

Combined  Compass  and  levels 15.00 

Alidade,  with  telescope  9  inches  long,  power  20  diame- 
ters, with  stadia,  vertical  circle  to  1  minute,  level  on 
telescope  and  clamp  and  tangent,  mounted  on  column  as 
in  engraving 70.00 


Price  as  shown,  total. 
205 


$130.00 


206  PLANE-TABLES 

The  plane-table  consists  mainly  of  a  drawing-board 
mounted  upon  a  firm  tripod,  as  shown  in  No.  553,  having 
upon  its  upper  surface  a  movable  straight-edge  or  alidade, 
arranged  either  with  sight  vanes  or  a  telescope,  by  which  it 
may  be  directed  to  any  point,  a  line  being  then  drawn  on  the 
paper  along  the  edge  of  the  alidade. 

A  square  brass  plate,  to  which  is  attached  a  compass  with 
two  spirit-levels,  is  also  shown,  and  serves  both 

COMPASS 

to  level  the  table  and,  when  applied  by  the 
edges  parallel  to  the  zero  lines  of  the  compass  circle,  to 
determine  the  magnetic  bearing  of  the  lines  drawn  on  the 
paper,  or  the  direction  of  the  table  itself. 

The  table  is  of  wood  arranged  in  sections  to  prevent 
warping,  and  has  an  adjustable  wooden  roller  at  each  end, 
DRAWING-  by  which  the  paper  is  brought  down  snugly  to 
BOARD  the  board,  or  upon  which  a  long  sheet  can  be 
rolled  and  unrolled.  Sometimes  in  place  of  the  rollers,  and 
often  in  connection  with  them,  a  number  of  brass  clamps  are 
used,  as  shown,  to  hold  the  paper  firmly. 

Another  method  of  fastening  the  paper  to  the  board  is 
shown  in  the  cut  on  page  211,  in  which  are  represented  small 
brass  screws  passing  through  the  paper  and  into  brass  sockets 
let  into  and  slightly  below  the  surface  of  the  board.  This 
method  allows  the  alidade  to  move  over  the  surface  without 
interference. 

The   plumbing-arm,    shown   in   the   figure,    has   its   end 

brought  to  a  point,  that  it  may  be  set  at   any  given  place 

upon  the  paper,  the  plummet  hanging  from  the 

ARM  under  arm  determining  the  corresponding  point 

on  the  ground.  The  lower  arm  moves  upon  a  hinge,  an 
index  on  the  side  showing  when  the  ends  of  the  two  arms  are 
plumb  with  each  other  as  applied  to  the  table. 


PLANE-TABLES 


207 


The  construction  of  the  socket  and  tripod  head  is 
shown  below,  a  representing  the  hemispherical  concave 
metal  cup  fastened  by  six  screws  to  the  wooden  top  of 
SOCKET  AND  tne  tripod,  b  the  upper  or  convex  part  fitting 

TRIPOD  into  the  cup  and  clamped  to  it  by  the  clamp- 

ing piece,  c,  and  nut,  d.  A  strong  spiral  spring  in  the 
hollow  cylinder  between  c  and  d  serves  to  hold  the  two 
spherical  surfaces  of  the  socket  together,  and  allows  the 
easy  movement  of  one  within  the  other  in  the  leveling  of 
the  table. 


The  flange  of  the  socket  b  supports  the  table,  and  is  con- 
nected with  it  by  three  segments  of  brass,  two  of  which  are 
shown  at  e  e.  The  table  can  be  oriented  at  will,  and  clamped 
by  a  milled-head  screw  passing  through  one  of  these  segments. 

PLANE-TABLE    WITH  LEVELING-SCREWS 
AND    TANGENT  MOVEMENT 

The  cut  on  page  208  shows  a  modification  of  the  simple 
plane-table,  there  being  added  a  tangent  movement  in  azimuth 
and  three  screws  for  leveling. 

The  board  appears  as  if  cut  away,  to  show  in  detail  the 
socket  and  leveling-screws  and  tangent  movement,  by  which 
a  more  delicate  orienting  may  be  obtained  than  by  the  method 
before  described. 


208 


PLANE-TABLES 


The  Plane-Table  outfit  shown  above  is  our  No.  549,  and 


costs  as  follows : 


PRICE 


Plane-Table,  board  30  x  24  inches,  mounted  on  large  tripod,  with 
leveling-socket  and  clamp,  and  with  plumbing-arm,  plummet, 

and  clamps  for  paper $45.00 

Set  of  three  leveling-screws 10.00 

Clamp  and  tangent,  for  movement  in  azimuth 10.00 

Combined  Compass  and  levels,  with  square  base 15.00 

Alidade,  with  telescope  11  inches  long,  with  stadia,  4^-inch  vertical 
circle  with  vernier  to  1  minute,  level  on  telescope  and  clamp 
and  tangent, on  column,  power  of  telescope  24  diameters 90.00 

Total..  ..$170.00 


PLANE-  TABLES  209 

TO  USE  THE  PLANE-TABLE 

The  tripod  is  set  up  firmly,  and  the  board  with  the  upper 
half  of  the  spherical  socket  attached  is  placed  upon  the  lower 
half  of  the  socket  fastened  to  the  tripod,  the  wing  clamping  - 
nut  being  screwed  up  until  the  table  is  secure  upon  the 
tripod.  The  board  is  moved  by  the  pressure  of  the  hand, 
or  by  the  leveling-screws,  until  the  level -bubbles  upon  the 
compass  plate  will  remain  in  the  middle  upon  any  part  of 
the  surface.  The  wing-nut  is  then  screwed  up  and  the  board 
made  firm  upon  the  tripod. 

Any  place  on  the  drawing-board  may  be  assumed  as  a 
starting  point,  its  position  over  a  given  point  on  the  ground 
being  determined  by  the  plumbing-arm  and  plummet.  From 
the  given  point  on  the  paper,  sights  can  be  taken  to  different 
corners  of  the  field,  and  lines  drawn  on  the  paper  along  the 
edge  of  the  alidade.  Thus  a  miniature  of  the  tract  can  be 
traced  on  the  paper,  the  bearing  of  any  line  being  ascertained 
by  applying  the  side  of  the  compass  plate  to  the  edge  of  the 
alidade  placed  on  that  line.  The  table  can  be  oriented, 
either  by  the  hand,  on  releasing  the  milled-head  screw 
which  clamps  the  flange,  or  by  the  tangent  screw  as  before 
described. 

The  measurement  of  distances  by  the  stadia  wires  of  the 
telescope,  and  of  vertical  angles  by  the  circle,  is  effected  as 
already  described  in  our  account  of  the  transit. 


210  PLANE-TABLES 

JOHNSON  IMPROVED  PLANE-TABLE 
MO  VEMENT 

We  illustrate  on  page  211  what  is  known  as  the  Johnson 
Plane-Table  movement,  complete  with  large  alidade,  plumbing- 
arm  and  compass. 

The  board  is  shown  as  cut  away,  to  give  a  better  view  of 
the  tripod  and  movement.  In  the  lower  corner  is  shown  the 
movement  alone,  with  a  portion  cut  away  to  show  the  con- 
struction. This  movement  has  been  largely  used  by  the 
topographers  of  the  U.  S.  Geological  Survey. 

As  shown,  this  movement  supplies  an  arrangement  where- 
by the  table  can  be  easily  made  horizontal  and  then  secured 
by  the  large  wing-nut,  A.  To  orient  the  board,  the  wing- 
nut,  B,  is  loosened,  leaving  the  hemispherical  surface,  bearing 
the  board  secured  to  the  flange,  free  to  turn,  and  it  can  be 
clamped  by  screwing  up  the  same  nut.  This  movement  as 
modified  in  recent  years  supplies  an  extremely  efficient  and 
portable  plane-table. 

The  movement  with  legs  complete  weighs  about  nine 
pounds.  The  legs  are  of  straight -grained  second-growth 
hickory,  and  the  construction  of  the  whole  tripod  is  such  as 
to  secure  strength  and  accuracy,  and  it  is  capable  of  standing 
rough  usage  without  getting  out  of  order. 

Any  of  the  alidades,  as  described  on  pages  212  to  214, 
can  be  used  with  the  Johnson  Plane-Table. 

See  pages  288  and  289  for  a  list  of  Johnson  Plane-Table 
outfits,  with  prices. 


PLANE-TABLES 


The  Johnson  Plane -Table  outfit  as  shown    above    is  our 
No.  576,  and  costs  as  follows  : 

PRICE 

Johnson  Improved  Plane-Table  movement,  mounted  on  large  tripod 935.00 

Plane-Table  Drawing- Board,  31  x  24  inches,  fitted,  and  with  screw-sockets  and 

clamps  for  paper 5.00 

Plumbing-arm  and  plummet 4.00 

Combined  Compass  and  levels  with  square  base 15.00 

Alidade,  with  telescope  11  inches  long,  with  stadia,  4%-inch  vertical  circle  with 
vernier  to  1  minute,   level  on  telescope  and  clamp  and  tangent)  on  column, 

power  of  telescope  24  diameters 90.00 


Total 


$149.00 


212 


ALIDADES 


ALIDADES 

The  patterns  of  our  plane-tables  vary  mainly  in  their  ali- 
dades, of  which  we  make  several  kinds. 


NO.   580.     Price,  $15.00. 

The  simplest  alidade  is  shown  above,  and  consists  of  a  brass 
ruler  or  straight-edge,  twenty  inches  long  and  about  three 
inches  wide,  at  the  ends  of  which  sight  vanes  are  mounted, 
like  those  of  the  compass.  The  edge  of  the  ruler  is  chamfered 
and  in  line  with  the  slots  of  the  vanes. 


NO.   581  .     Price,  $50.00. 

The  figure  No.  581  shows  the  alidade  to  which  is  fitted  the 
telescopic  sight,  having  a  level,  clamp  and  tangent,  and  verti- 
cal circle  reading  to  five  minutes  attached  to  the  telescope, 
which  has  also  stadia  wires.  The  telescope  is  placed  in  line 
with  the  fiducial  edge. 


ALIDADES 


213 


Another  pattern  of  alidade,  No.  582,  is  shown  in  the  cut 
of  the  plane-table  on  page  205,  the  brass  ruler  being  three 
inches  wide.  The  column  supports  the  telescope  with  its 
attachments.  The  vertical  circle  is  graduated  on  silver  and 
reads  to  one  minute.  The  telescope  is  nine  inches  long  with 
a  power  of  twenty  diameters,  and  is  provided  with  stadia  wires 
and  adjusted  like  the  telescope  of  the  transit. 


NO.   583.     Price,  $90.00. 

In  the  alidade  shown  in  No.  583  the  telescope  is  the  same 
as  that  used  in  our  best  transits,  having  level,  clamp  and 
tangent,  vertical  circle  graduated  on  silver  and  reading  to 
one  minute,  and  stadia  wires  for  measuring  distances. 

It  is  placed  on  a  brass  ruler  four  inches  wide,  and  is 
adjusted  and  used  in  the  same  manner  as  the  one  just 
described. 


214 


ALIDADES 


NO.  584A 

In  alidade  No.  584A,  shown  in  the  cut,  the  blade  is 
eighteen  inches  long  and  three  inches  wide,  and  carries  a 
circular  spirit-level,  and  a  telescope  eleven  inches  long  with 
stadia  wires,  detachable  striding-level,  vertical  arc  and  axis 
tangent,  mounted  on  a  column.  For  easy  adjustment  of  the 
line  of  collimation  the  telescope  can  be  turned  on  its  axis 
through  180°.  The  vertical  arc  reads  by  vernier  to  one 
minute,  and  as  the  zero  is  at  one  end  all  the  angles  read  are 
positive. 

The  telescope  is  made  either  inverting  or  erecting,  as 
desired,  and  is  fitted  with  a  diagonal  prism  with  darkener,  as 
shown.  A  rectangular  box  compass,  with  four-inch  needle, 
and  attached  to  the  alidade,  is  also  furnished  when  desired. 

No.  584 A     Price,  as  shown,  with  inverting  eye-piece $118.00 

No.  584B     Price,  as  shown,  but  with  erecting  eye-piece 118.00 

Price  of  Box  Compass,  as  above,  $10.00. 
Beaman  Stadia  Arc,  No.  149,  can  be  fitted  to  this  Alidade,  at  an  extra  cost  of  $15.00. 


TRAVERSE  PLANE-TABLE  215 

TRAVERSE  PLANE-TABLE 

The  cut,  No.  586,  represents  a  simple  form  of  plane-table 
and  alidade,  first  made  by  us  for  the  U.  S.  Geological  Survey, 
and  in  its  present  improved  form  used  extensively  for  traverse 
work.  The  board  is  fifteen  inches  square,  arid  has  on  its 
under  side  a  strong  brass  flange  with  spring,  in  which  the 
plunger  clamp  of  the  tripod  head  engages,  allowing  the  board 
to  be  clamped  or  oriented  as  desired.  Small  clamp  screws 
with  sockets  for  holding  the  paper  are  often  placed  at  the 
corners  of  the  board. 


NO.   586 
Price  as  shown,  $30.00 ;  if  the  tripod  has  extension  legs,  add  extra  $5.00. 

The  alidade  consists  of  a  brass  ruler  ten  inches  long,  grad- 
uated on  the  beveled  edge  to  a  scale  of  forty  parts  to  the  inch, 
and  having  at  each  end  hinged  sights  which  fold  close  to  the 
surface  of  the  ruler.  The  alidade  is  furnished  with  a  leather 


216  TRAVERSE  PLANE-TABLE 

pouch.  Inserted  in  one  edge  of  the  board  is  a  small  box 
compass  with  needle  about  four  inches  long. 

The  tripod  legs  are  attached  to  a  head  which  has  a 
clamping-screw  passing  through  its  center,  compressing  a 
concealed  spring  and  holding  the  board  to  the  tripod  head 
when  oriented  to  position. 

The  whole,  while  not  capable  of  as  accurate  work  as  the 
larger  plane-tables,  constitutes  a  light  and  portable  instrument 
for  topography. 

POCKET  ALIDADES 

A  pocket  alidade,  of  a  pattern  like  the  one  shown  with 
the  Traverse  Plane -Table,  is  made  six  inches  long  and  has 
hinged  sights  which  fold  close  to  the  ruler.  The  beveled  edge 
is  graduated  to  scale  of  one  forty -five -thousandth  and  one 
ninety -thousandth,  each  graduation  representing  respectively 
one-twentieth  or  one-fiftieth  of  a  mile. 

Price,  in  leather  pouch $7.50 

Another  form  of  the  pocket  alidade  is  made  seven  inches 
long,  with  a  peep  hole  for  the  near  sight,  and  for  the  other 
a  folding  sight  graduated  for  a  vertical  scale  representing  a 
rise  of  twenty-five  feet  to  the  mile.  The  beveled  edge  is 
graduated  the  same  as  the  six-inch  alidade  described  above. 
The  ruler  carries  an  adjustable  level  with  knurled-head 
leveling-screw. 

Price,  in  leather  pouch $12.00 

See  page  289  of  the  Price  List. 


BATSON  SKETCHING-CASE 

PATENTED 


NO.  595.     Price, 

E  engraving  shows  the  Batson  Sketching-Case,  designed 
for  the  use  of  civil  and  military  engineers  and  surveyors 
in  reconnoissance  and  topographical  surveys.  It  was  given  an 
extensive  and  successful  trial,  in  1898  and  1899,  in  Cuba  and 
the  Philippines,  as  well  as  in  the  United  States. 

This  instrument  is  a  small  drawing-board,  having  upon  its 
upper  surface  a  movable  graduated  circle,  carrying  a  small 
alidade  with  scales.  At  one  end  of  the  board  are  a  compass 
and  a  clinometer. 

The  drawing-board  is  of  wood  and  is  provided  with  rollers 
which  carry  the  paper  for  recording  observations.  Friction 
brakes  hold  the  rollers,  so  that  the  paper  is  held  down  snugly 
to  the  board  and  prevented  from  uncoiling.  Six  holes  at  the 
end  of  the  board  opposite  the  compass  afford  receptacles  for 
the  pencils  used  in  topographical  sketching. 

'   217 


218  3ATSON  SKETCHING-CASE 

The  protractor  is  held  in  position  by  a  carrier  which  slides 
upon  a  bar  attached  to  the  wooden  end -pieces,  as  shown. 
The  construction  of  the  carrier  allows  the  protractor  to  be 
turned,  or  to  be  clamped  by  means  of  two  set-screws,  if 
desired.  The  protractor  can  also,  be  lifted  to  an  upright 
position,  by  pulling  back  the  spring  catch  at  the  end  of  the 
carrier  bar. 

The  alidade  turns  within  the  graduated  circle,  and  with  it 
forms  the  protractor. 

The  paper  for  use  with  this  instrument  is  six  inches  wide, 
and  from  thirty  to  forty  inches  is  found  to  be  a  convenient 
length. 

The  sketching -case  is  fitted  with  a  strap  for  carrying  on 
the  forearm,  and,  if  desired,  is  provided  with  a  short,  light 
staff  or  a  tripod,  for  use  in  taking  bearings  on  reference 
points  and  on  objects  which  it  is  desirable  to  locate  more 
accurately  than  is  possible  when  holding  the  instrument  in 
the  hand. 

A  sole-leather  case,  having  a  pocket  for  the  instrument  and 
another  for  sketches  and  extra  paper,  and  fitted  with  lock  and 
shoulder  strap,  is  provided  with  each  instrument. 

TO  MOUNT    THE  PAPER 

Raise  the  protractor  to  a  vertical  position.  Holding  the 
board  with  compass  to  the  right,  insert  one  end  of  the  paper 
in  the  slit  of  the  far  roller  and  turn  the  roller  toward  the 
board  until  only  seven  or  eight  inches  of  the  paper  are  left 
free,  then  insert  the  free  end  in  the  slit  of  the  near  roller  and 
turn  the  roller  toward  the  board  until  the  paper  is  taut. 
Release  the  protractor  and  turn  it  down  on  the  board. 


BATS  ON  SKETCHING-CASE  219 

TO  SET   THE  INSTRUMENT 

Release  the  needle.  Face  in  the  general  direction  of  the 
route  to  be  mapped  and  hold  the  instrument  in  the  left  hand 
with  the  compass  to  the  right ;  or,  having  it  set  up  on  the  staff, 
orient  it  until  the  long  way  of  the  paper  is  in  the  general  direc- 
tion of  the  route  to  be  mapped,  and  the  compass  to  the  right. 
Hold  steadily  and  read  the  bearing.  Unclamp  the  protractor 
and  turn  it  until  the  index  on  the  upper  plate  of  the  carrier 
indicates  the  same  reading  on  the  protractor  that  is  shown  by 
the  needle.  The  instrument  is  now  set,  and,  if  the  ruler  be 
turned  to  zero,  it  will  lie  in  the  magnetic  meridian. 

TO   PLACE    THE    CENTER    OF    THE    PROTRACTOR 

AND    THE  ZERO   OF    THE  SCALES  OVER 

ANY  POINT  ON   THE  PAPER 

Move  the  paper  by  turning  one  of  the  rollers  until  the 
given  point  is  opposite  the  center  of  the  protractor.  Unclamp 
the  carrier  of  the  protractor  and  slide  it  along  the  bar  until 
the  center  of  the  protractor  is  over  the  point. 

SCALES 

The  alidade  carries  two  scales.  The  one  on  the  right  of 
the  slit,  when  the  clamping-arm  is  to  the  right,  is  graduated 
six  inches  to  one  mile,  and  the  one  on  the  left  eight  inches  to 
one  mile,  each  reading  to  twelve  and  one-half  yards.  Should 
it  be  desired  to  use  a  scale  of  three  inches  to  one  mile,  or  four 
inches  to  one  mile,  use  the  six-inch  or  eight-inch  scale  respec- 
tively, giving  the  smallest  reading  a  value  of  twenty-five  yards. 
In  the  same  way  a  scale  of  one  and  one-half  inches  to  one 
mile,  or  two  inches  to  one  mile,  may  be  obtained,  the  smallest 
reading  being  fifty  yards.  If  the  distance  is  measured  by 
counting  paces,  find,  by  pacing  over  a  measured  distance,  the 


220  BATSON  SKETCHING-CASE 

number  of  steps  or  alternate  steps  taken  in  one  hundred  yards ; 
then,  for  each  time  this  number  of  steps  is  counted,  score  one 
hundred  yards.  The  total  score  will  then  be  in  yards,  and  is 
marked  off  on  the  scale  of  yards.  This  method  will  be  found 
to  cause  no  confusion.  The  soldier  is  trained  to  estimate  dis- 
tances in  yards,  and,  as  much  estimating  of  distances  is 
required  in  topographical  work,  a  greater  degree  of  accuracy 
can  be  obtained  if  only  a  scale  of  yards  is  used  than  if  a  scale 
of  steps  is  used  when  the  distance  is  paced,  and  a  scale  of 
yards  when  the  distances  are  estimated. 

The  latter  method  is  also  open  to  the  objection  that  two 
scales  must  be  prepared  before  beginning  the  work.  Few 
non-commissioned  officers  and  privates  understand  scales 
sufficiently  to  construct  one,  although  but  little  explanation 
is  necessary  to  enable  them  to  use  one  already  constructed. 

For  keeping  tally  a  tally  register  is  most  convenient,  but 
any  small  pasteboard  counter  will  answer. 

TO   USE    THE  SKETCHING-CASE 

Set  the  instrument  as  explained.  Select  a  point  on  the 
paper  for  the  initial  station.  This  point  should  ordinarily  be 
AS  A  about  midway  between  the  edges  of  the  paper ; 

PLANE-TABLE  but  when  it  is  known  that  the  route  to  be 
traveled  deviates  considerably  to  one  side  or  the  other  from 
the  general  direction,  then  the  point  should  be  selected  on  the 
opposite  side  of  the  paper.  The  instrument  should  always 
be  so  set  and  the  point  representing  the  initial  station  so 
selected,  that  as  much  of  the  map  as  possible  may  be  sketched 
without  running  off  the  paper. 

Having  selected  the  point  representing  the  first  station, 
center  the  protractor  over  this  point.  Holding  the  instru- 
ment in  the  left  hand,  or  having  it  mounted  on  the  staff, 


BA  TSON  SKE  TCHING-  CASE  22 1 

orient  it  until  the  reading  of  the  needle  corresponds  with  the 
reading  of  the  protractor  circle.  Holding  it  steady  in  this 
position,  turn  the  alidade  upon  all  objects  it  is  desired  to 
plot  on  the  map,  and  draw  light  lines  in  the  slit  from  the 
station  point  toward  them.  These  objects  should  include 
the  next  station  to  be  occupied.  After  having  taken  the 
slopes  in  the  vicinity  and  sketched  in  the  detail,  the  ruler  is 
clamped  in  the  direction  of  the  next  station. 

With  the  protractor  set  as  previously  explained,  orient 
BY  PLOTTING  THE  tne  instrument  until  the  right-hand 
COMPASS  READINGS  edge  of  the  board  is  in  line  with 
the  object  to  be  plotted  upon  the  map,  and  read  the  com- 
pass. Turn  the  ruler  to  the  corresponding  reading  on  the 
protractor  circle. 

Bearings  taken  with  the  box  or  prismatic  compass  may  tie 
plotted  upon  the  map  in  the  same  manner. 

PRICES 

Batson  Sketching-Case,  as  shown,  with  leather  case $30.00 

Wooden  Staff,  about  two  feet  long,  with  steel-pointed  shoe 1.00 

Plain  Tripod,  about  3£  feet  long 3.50 


CURRENT  METER 


'T^HE  Price  Current  Meter,  shown  on  page  224,  was 
devised  by  W.  G.  Price,  then  a  U.  S.  Assistant  Engi- 
neer, after  an  experience  of  six  years  in  measuring  the 
velocity  of  water  in  the  Ohio  and  Mississippi  rivers  by  differ- 
ent methods.  The  instrument  is  used  by  the  U.  S.  Engineer 
Corps,  the  U.  S.  Coast  and  Geodetic  Survey,  and  by  hydraulic 
engineers  in  different  parts  of  the  country. 

The  wheel  of    this   meter  carries  five 

BUCKET  WHEEL  .      .     .        . 

conical  buckets,  as  shown,  so  arranged 
that  the  force  of  the  slightest  current  will  cause  the  wheel 
te  revolve. 

The  ends  of  the  axis  of  the  wheel  revolve  in  bearings 
contained  in  air  chambers  of  metal,  which  afford  protection 
from  the  water  and  any  gritty  matter  it  may  contain.  The 
friction  is  thus  reduced  to  a  minimum  and  made  a  constant 
quantity.  The  form  of  the  wheel  and  buckets  is  such  as  to 
insure  great  strength  and  thus  resist  injury  from  driftwood, 
while  at  the  same  time  they  are  not  liable  to  obstruction  from 
floating  leaves  and  grass. 

The  upper  end  of  the  axis  of  the  wheel  extends 

AXIS  , 

above  its  bearing,  entering  an  air-tight  metal  box 
hereafter  named,  and  is  cut  down  for  a  short  distance,  form- 
ing an  eccentric. 

A  light  spring,  so  arranged  that  it  comes  in  contact  with 
the  eccentric,  bears  upon  this  divided  part  of  the  axis,  and 
successively  makes  and  breaks  the  electric  current  as  the  wheel 
revolves. 

The  spring  and  divided  axis  form  the  contact-breaker,  and 
223 


224 


CURRENT  METERS 


LEAD  WEIGHT 
AND  ROD 
Price, 


NO.  606 


NO.  609 

ELECTRIC   REGISTER 
Price,  $50.00. 


CURRENT  METERS  225 

are    both    contained    in    the    metal    air-tight   box    which    is 
shown  in  the  cut. 

A  hollow  cylinder  of  bronze,  called  the  trunnion,  fitting 

easily  upon  the  rod,  supports  the  frame  of  the  meter  by  a  pivot 

on  each  side.     Thus  by  the  rod  and  pivots  the 

TRUNNION  ...  , ,   '          .  ., 

meter  is  free  to  move  both  horizontally  and  ver- 
tically, and  so  adjust  itself  to  the  direction  of  the  current. 

The  frame  of  the  meter  is  of  bronze,  and  is  very  solid  and 
strong.  The  rudder  has  four  light  metal  wings  or  vanes, 
FRAME  AND  secured  to  a  central  rod,  and  is  made  to  balance 
RUDDER  •  the  weight  of  the  wheel  and  give  direction  to 
it,  and  thus  keep  the  wheel  in  both  directions  in  line  with  the 
current.  The  meter  frame  has  a  hinged  side  secured  by  a 
spring  key,  allowing  the  meter  and  trunnion,  which  is  itself  in 
two  parts,  to  be  detached  from  the  rod  when  desired.  In  the 
older  form  the  trunnion  was  left  on  the  rod.  The  connecting 
-wires  are  passed  upward  through  the  trunnion  of  the  meter, 
and  so  have  no  tendency  to  pull  the  meter  out  of  the  line  of 
the  current. 

The  rod  is  of  brass,  three-quarters  of  an  inch  in  diameter 
and  two  feet  long,  its  upper  end  having  an  eye  of  brass 
screwed  firmly  on  and  pinned,  and  its  lower  end  screwed  into 
a  brass  socket  in  the  lead  weight,  B,  and  secured  thereto  by  a 
jam-nut.  A  sliding  ring  of  metal  with  set-screw,  as  shown, 
allows  the  meter  to  be  raised  to  any  point  on  the  rod. 

The  weight,  No.  606,  is  of  lead  and  weighs  about  sixty 

pounds.     It  has  a  rudder  of  wood,  as  shown,  secured  to  the 

weight  by  brass  cheek  pieces,  which  are  also 

LEAD    WEIGHT  ' 

securely  fastened  to  the  weight  by  sockets 
cast  in  the  lead.  The  rudder  can  be  set  at  an  angle  with  the 
weight,  or  turned  up  parallel  with  the  rod  for  convenience  in 
transportation. 


226  CURRENT  METERS 

The  weight,  B,  is  only  necessary  where  the  meter  is  used 
in  deep  water  and  harbor  surveying,  where  the  currents  are 
very  strong.  In  shallower  water  the  meter  is  suspended  upon 
a  brass  rod.  These  rods  are  each  four  feet  long,  and  can  be 
screwed  together  when  a  long  length  is  needed.  They  are 
graduated  to  feet  and  tenths. 

SIZE  OF   THE  METER 

This  meter  has  a  wheel  six  inches  in  diameter,  and  the 
total  length,  including  the  rudder  vane,  is  about  twenty -four 
and  one-half  inches.  It  is  adapted  for  deep  water  and  harbor 
surveying,  and  also  for  use  in  smaller  rivers  and  streams,  and 
is  used  either  with  or  without  the  weight. 

RATING    THE  METER 

Before  using  the  meter  it  is  necessary  to  obtain  its  rating, 
which  is  the  number  of  revolutions  of  its  wheel  made  in  pass- 
ing over  a  measured  distance,  at  different  velocities.  The 
meter  should  be  rated  in  still  water  which  is  not  less  than 
five  feet  deep,  and  to  secure  a  good  rating  there  should  be 
but  little  wind. 

It  should  be  attached  to  the  bow  of  a  skiff,  as  shown  in 
the  cut,  and  immersed  not  less  than  two  feet.  The  boat 
should  have  no  rudder.  The  observer  should  stake  out  two 
parallel  range  lines  on  shore,  about  two  hundred  feet  apart 
and  at  right  angles  with  the  course  the  boat  is  to  take. 

Attach  a  quarter-inch  cotton  cord  about  three  hundred 
feet  long  to  the  bow  of  the  boat,  and  pass  it  around  a  pulley 
which  is  placed  in  line  with  the  course.  If  there  is  a  bend 
in  the  shore  the  pulley  may  not  be  necessary. 

It  will  require  three  or  four  men  to  pull  the  boat  fast 
enough  for  the  high  velocities,  and  there  must  be  a  man  with 
oars  in  the  boat  with  the  observer,  to  prevent  its  running 
into  the  shore. 


CURRENT  METERS  227 

Haul  the  boat  over  the  measured  base  at  very  slow,  very 
fast,  and  medium  velocities,  which  should  be  as  nearly  uniform 
as  possible  during  each  passage. 

Before  each  trial  note  if  the  meter  is  free  to  point  in  the 
direction  of  the  current,  as  in  backing  over  the  course  the 
connecting  wires  are  liable  to  become  twisted  so  as  to  pull  the 
meter  out  of  line. 


Fasten  a  vertical  rod  on  the  boat  near  the  seat  of  the 
observer,  to  enable  him  to  sight  ^t  the  range  stakes  as  he 
passes  them.  Start  the  time-recorder,  see  No.  619  of  the 
Price  List,  and  electric  register  on  the  first  range  line,  and 
stop  them  on  the  second.  Note  accurately  the  time  as  given 
by  the  time  recorder,  and  the  number  of  revolutions  of  the 
wheel  as  indicated  by  the  register. 

The  rating  of  a  meter,  which  is  the  value  in  feet  per  second 
of  one  revolution  of  the  wheel,  will  not  change  as  long  as  the 
wheel  turns  freely 'and  has  not  been  seriously  injured. 

The  velocity  of  a  current  of  water  can  readily  be  com- 
puted from  the  Reduction  Table  furnished  with  each  instru- 
ment, which  is  also  given  on  page  229,  the  number  of 
revolutions  of  the  wheel  per  second  having  been  already 
ascertained  by  observation,  and  recorded  by  the  register. 

Should  the  observer  require  greater  accuracy,  it  is  advisable 
that  the  individual  rating  of  each  meter  be  obtained.  If 


228  ELECTRIC  REGISTER  AND   BATTERY 

• 

desired,  we  will  rate  the  meter  and  furnish  a  reduction  table, 
at  a  cost  of  about  thirteen  dollars. 

ELECTRIC  REGISTER 

The  number  of  revolutions  of  the  meter  wheel  is  recorded 
by  an  electric  register,  shown  in  No.  609,  actuated  by  a  bat- 
tery of  three  cells. 

-  The  electric  current  proceeding  from  one  pole  of  the 
battery  is  carried  by  an  insulated  copper  wire  down  through 
the  trunnion  of  the  meter,  and  thence  up  to  the  insulated 
binding-post  on  the  upper  arm,  as  shown  in  the  cut ;  thence 
through  the  contact  breaker,  the  axis  of  the  wheel  and  the 
lower  arm,  to  the  binding-screw  shown  on  that  arm ;  thence 
by  a  second  copper  wire  up  through  the  trunnion  to  one 
binding-screw  of  the  register ;  thence  through  the  register  to 
the  other  binding-post ;  and  thence,  finally,  by  another  wire 
to  the  other  pole  of  the  battery. 

The  electric  register  is  enclosed  in  a  brass  case,  showing 
three  dials  under  a  glass  face,'  and  has  an  electro -magnet 
which,  when  the  circuit  is  made,  moves  a  lever  at  the  end 
of  which  is  a  pawl  carrying  forward  a  ratchet  wheel  one  tooth 
at  every  contact  of  the  current.  The  large  dial  is  graduated 
into  one  hundred  spaces  and  the  two  small  dials  into  ten 
spaces  each,  all  reading  from  left  to  right.  The  large  dial 
counts  each  revolution  up  to  one  hundred, 'the  small  dial  on 
the  right  counts  one  thousand  revolutions  by  each  hundred, 
and  the  small  dial  on  the  left  counts  ten  thousand  revolutions 
by  each  thousand,  all  indicated  by  the  figuring. 

We    furnish   a   wet-cell    battery  to    operate    the    electric 
register.     The  battery  is  composed  of  three  cells 
in  a  wooden  case,  with  lock  and  strap.     See  No. 
612  of  the  Price  List. 


CURRENT  METERS 


229 


REDUCTION   TABLE  FOR  USE  WITH 
ELECTRIC    CURRENT    METER,   PATTERN   No.  600 

This  table  is  a  mean  of  the  ratings  of  several  different  Meters  and 

will  give  correct  values  within  one  per  cent,  for  any 

Meter  of  its  pattern  when  in  good  order. 


REV. 
PER  SEC. 

VHLOC. 
FEET 
PER  SEC. 

REV. 
PER  SEC. 

VELOC. 
FEET 
PER  SEC. 

REV. 
PER  SEC. 

VELOC. 
FEET 
PER  SEC. 

REV. 
PER  SEC. 

VELOC. 
FEET 
PER  SEC. 

0.00 

0.16 

1.00 

3.33 

2.00 

6.35 

3.00 

9.24 

.05 

.31 

1.05 

3.48 

2.05 

6.50 

3.05 

9.38 

.10 

.46 

1.10 

3.63 

2.10 

6.65 

3.10 

9.52 

.15 

.62 

1.15 

3.78 

2.15 

6.79 

3.15 

9.66 

.20 

.79 

1.20 

3.94 

2.20 

6.94 

3.20 

9.79 

.25 

.95 

1.25 

4.10 

2.25 

7.08 

3.25 

9.93 

.30 

1.11 

1.30 

4.25 

2.30 

7.23 

3.30 

10.07 

.35 

1.26 

1.35 

4.40 

2.35 

7.37 

3.35 

10.21 

.40 

1.42 

1.40 

4.55 

2.40 

7.52 

3.40 

10.35 

.45 

1.58 

1.45 

4.70 

2.45 

7.67 

3.45 

10.49 

.50 

1.75 

1.50 

4.86 

2.50 

7.82 

3.50 

10.63 

.55 

1.91 

1.55 

5.01 

2.55 

7.96 

3.55 

10.77 

.60 

2.07 

1.60 

5.16 

2.60 

8.10 

3.60 

10.91 

.65 

2.23 

1.65 

5.31 

2.65 

8.24 

3.65 

11.05 

.70 

2.38 

1.70 

5.46 

2.70 

8.39 

3.70 

11.19 

.75 

2.53 

1.75 

5.61 

2.75 

8.53 

3.75 

11.33 

.80 

2.69 

1.80 

5.75 

2.80 

8.67 

3.80 

11.47 

.85 

2.85 

1.85 

5.90 

2.85 

8.81 

3.85 

11.61 

.90 

3.01 

1.90 

6.05 

2.90 

8.95 

3.90 

11.74 

.95 

3.17 

1.95 

.    6.20 

2.95 

9.10 

3.95 

11.88 

4.00 

12.02 

REDUCTION  TABLE 


To  be  used  in  reducing  observed  velocities  to  the  mean  vertical 

velocity.     The  mean  velocity  is  about  ninety-six 

per  cent,  of  the  mid-depth  velocity. 


DEPTH 

PER  CENT. 

DEPTH 

PER  CENT. 

DEPTH 

PER  CENT. 

J 

0.952 
0.951 

T40 
& 

0.953 
0.960 

t 

0.984 
1.020 

s 

0.948 

T60 

0.965 

.;* 

1.140 

MULTIPLY  THE  MEASURED  VELOCITY  BY  THE  PERCENTAGE. 


CURRENT  METERS 


231 


PRICE  ACOUSTIC  CURRENT  METER 

PATENTED 

This  meter  was  devised  by  W.  G.  Price,  and  has  many 
points  of  excellence.  It  is  very  compact,  light,  and  portable, 
and  is  especially  designed  for  use  in  irrigation  ditches  or  in 
streams  where  there  is  little  depth  of  water.  The  cut  shows 
-the  external  appearance  of  the  meter,  with  the  brass  tubes 
by  which  it  is  held  while  in  use. 
The  revolutions  of  the  wheel  are  indi- 
cated by  a  hammer  striking  against 
a  diaphragm,  one  blow  for  every  ten 
revolutions,  and  the  recording  mech- 
anism is  enclosed  in  the  stem  of  the 
meter  and  thoroughly  protected  from 
injury.  The  sound  of  the  recording 
stroke  is  transmitted  through  the 
tubing  suspending  the  meter,  and  is 
conveyed  to  the  ear  of  the  operator 
by  the  rubber  ear-tube.  In  use,  the 
operator  fixes  the  ear-tube  in  posi- 
tion by  a  rubber  band  passing 
around  his  head,  and  thus  both 
hands  are  left  free  for  the  manipu- 
lation of  the  meter.  Results  obtained  may  be  readily  reduced 
by  the  use  of  the  Reduction  Table  supplied  with  the  meter, 
and  also  given  on  page  232. 

Each  meter  is  packed  in  a  wooden  box  with  lock  and 
strap,  and  is  provided  with  two  lengths  of  nickel-plated 
brass  tubing,  graduate/!  to  feet  and  tenths  up  to  four  feet,  and 
with  four  feet  of  rubber  tubing  with  all  necessary  connec- 
tions. Extra  graduated  brass  tubing,  in  lengths  of  two 
feet,  can  be  furnished  at  a  cost  of  $2.50  per  length. 


NO.  616 

Price,  $50.00. 


232 


CURRENT  METERS 


REDUCTION  TABLE   FOR   USE  WITH 

PRICE   PATENT  ACOUSTIC  -  CURRENT  METER 

PATTERN  No.  616 

This  table  is  a  mean  of  the  ratings  of  fourteen  meters,  and 
will  probably  give  correct  values  within  one  per  cent,  for  any 
meter  of  its  pattern  when  in  good  order. 

The  time  column  is  the  number  of  seconds  that  have 
elapsed  during  one  hundred  revolutions  of  the  wheel,  there 
being  ten  revolutions  to  each  rap. 


jj 

M 

H 

H 

H 

M 

t 

S 

^ 

8 

B 

I 

X 

x 

H 

H 

H 

H) 

M 

H 

M 

H 

M 

1000 

0.27 

111 

2.11 

59 

3.96 

37 

6.28 

666 

.39 

105 

2.22 

57 

4.08 

36 

6.51 

500 

50 

100 

2.34 

56 

4.20 

34 

6.74 

400 

.61 

95 

2.46 

54 

4.31 

33 

6.98 

333 

.72 

91 

2.57 

53 

4.43 

32 

7.21 

286 

.83 

87 

2.69 

51 

4.54 

31 

7.44 

250 

.95 

83 

2.80 

50 

4.66 

30 

7.67 

222 

.07 

80 

2.92 

49 

4.78 

29 

7.91 

200 

.18 

77 

3.03 

48 

4.90 

28 

8.25 

182 

.30 

74 

3.15 

46 

5.01 

27 

8.48 

167 

.42 

71 

3.26 

45 

5.12 

26 

8.83 

154 

.53 

69 

3.38 

44 

5.24 

25 

9.29 

143 

.65 

67 

3.50 

43 

5.35 

24 

9.64 

133 

.77 

65 

3.61 

42 

5.58 

23 

10.10 

125 

.88 

62 

3.73 

40 

5.82 

22 

10.56 

118 

.99 

61 

3.85 

38 

6.05 

21 

11.02 

CURRENT  METERS 


233 


ELECTRIC  CURRENT  M-ETER,    WITH   VANE  AND 
LEAD    WEIGHT 


FOR  USE  IN  SMALL  STREAMS 
i 


NO.  617 

Price,  as  shown,  $60.00. 

The  importance  of  correct  hydraulic  measurements  has 
brought  the  current  meter  into  general  use,  and  while  our  No. 
600  has  long  been  regarded  as  a  standard  instrument  for 
observations  on  large  streams,  there  has  been  in  recent  years 
a  demand  for  a  light  and  serviceable  meter  for  use  in  small 
streams  and  irrigation  or  drainage  ditches. 

In  response  to  this  demand  the  Acoustic  Current  Meter? 


234  CURRENT  METERS 

indicating  by  sound  the  revolutions  of  the  wheel,  was  intro- 
duced, and  has  met  with  a  favorable  reception  by  hydraulic 
engineers.  Many  observers,  however,  prefer  that  the  revolu- 
tions of  the  wheel  should  be  indicated  by  the  making  and 
breaking  of  an  electric  current. 

For  some  time,  assisted  by  the  suggestions  of  the  engineers 
in  charge  of  the  U.  S.  Geological  Survey,  we  have  been  per- 
fecting the  small  Electric  Current  Meter  shown  in  the  cut, 
and  listed  as  our  No.  617.  While  constructed  practically 
along  the  lines  of  Current  Meter  No.  600,  this  meter  has  the 
advantage  of  extreme  lightness,  weighing  only  about  two 
pounds. 

The  electrical  connection  is  made  in  the  same  manner  as 
described  in  our  No.  600.  The  instrument  is  supported  in  a 
trunnion,  and  is  free  to  swing  in  a  vertical  plane.  The  vane 
is  so  made  that  it  may  be  taken  apart  for  convenience  in 
transportation. 

In  use,  the  meter  is  suspended  by  a  cable  containing  the 
wires  for  electrical  connection,  and  is  held  steady  by  a  lead 
weight,  as  shown  in  the  cut. 

The  electric  sounder  as  now  made  consists  of  an  ear-piece 
similar  to  that  used  on  the  telephone,  attached  to  a  small 
leather  case  containing  the  battery  with  either  a  bi-sulphate 
of  mercury  or  a  dry  cell. 

Every  revolution  of  the  wheel  is  indicated  by  the  ear- 
piece, the  observer  being  required  to  count  the  number  of 
revolutions  in  a  certain  period  of  time. 

A  strap  attached  to  the  battery  case  permits  the  sounder 
to  be  secured  to  the  shoulder  of  the  observer  in  such  a  way 
that  he  may  note  the  revolution  of  the  wheel  and  have  his 
hands  free  to  manipulate  the  meter. 

The  weight  is  now  made  in  torpedo  form  and  provided 


CURRENT  METERS  235 

with  vanes,  so  that  it  will  readily  take  the  direction  of  the 
current. 

The  meter  is  packed  in  a  strong  wooden  box,  large  enough 
to  contain  the  meter,  lead  weight,  sounder,  wire,  and  other 
apparatus  for  the  observer. 

A  table  for  reducing  observations  has  been  prepared  which 
will  give  correct  values  within  one  per  cent.  Shotild  greater 
accuracy  be  required,  it  is  advisable  that  the  individual  rating 
of  each  meter  be  obtained.  If  desired,  we  will  rate  the 
meter,  furnishing  table  at  a  cost  of  from  twelve  to  thirteen 
dollars. 

PRICES 

Meter  No.  617 $50.00 

Lead  Weight,  torpedo  form 3.50 

Electric  Sounder,  with  telephone  ear-piece  and  twenty  feet  of  cable.    10.00 
Meter  No.   617,  complete  with  lead  weight,   electric  sounder  and 

twenty  feet  of  cable 63.50 

Extra  length  of  cable,  5  cents  per  foot. 

Special  Commutator  box,  applicable  to  Current  Meter  No.  617,  so 
arranged  that  either  every  revolution  or  every  fifth  revolution  of 
the  bucket  wheel  may  be  indicated,  making  it  possible  to  regis- 
ter very  high  velocities 15.00 


236 


CURRENT  METERS 


REDUCTION   TABLE   FOR   USE   WITH 
ELECTRIC    CURRENT    METERS,   Nos.  617   AND   618 

This  table  is  a  mean  of  the  ratings  of  ten  different  Meters,  and 

will  probably  give  correct  values  within  one  per  cent. 

for  any  Meter  of  its  pattern  in  good  order. 


REV. 
PER  SEC. 

VELOC. 
FEET 
PER  SEC. 

REV. 

PER  SEC. 

VELOC. 
FEET 
PER  SEC. 

REV. 

PER  SEC. 

VELOC. 
FEET 
PER  SEC. 

REV. 
PER  SEC. 

VELOC. 
FEET 
PER  SEC. 

.00 

.07 

.00 

2.38 

2.00 

4.71 

3.00 

7.03 

.05 

.18 

.05 

2.50 

2.05 

4.82 

3.05 

7   14 

.10 

.29 

.10 

2.62 

2.10 

4.99 

3.10 

7.26 

.15 

.40 

.15 

2.73 

2.15 

5.05 

3.15 

7.38 

.20 

.52 

.20 

2.85 

2.20 

5.17 

3.20 

7.50 

.25 

.64 

.25 

2.96 

2.25 

5.29 

3.25 

7.61 

.30 

.76 

.30 

3.07 

2.30 

5.41 

3.30 

7.73 

.35 

.87 

.35 

3.19 

2.35 

5.52 

3.35 

7.84 

.40 

.99 

.40 

3.31 

2.40 

5.64 

3.40 

7.96 

.45 

1.10 

.45 

3.43 

2.45 

5.75 

3.45 

8.08 

.50 

1.22 

.50 

3.55 

2.50 

5.87 

3.50 

8.20 

.55 

1.34 

.55 

3.66 

2.55 

5.98 

3.55 

8.31 

.60 

1.46 

.60 

3.78 

2.60 

6.10 

3.60 

8.43 

.65 

1.57 

.65 

3.90 

2.65 

6.22 

3.65 

8.54 

.70 

1.69 

.70 

4.01 

2.70 

6.34 

3.70 

8.66 

.75 

1.80 

.75 

4.12 

2.75 

6.45 

3.75 

8.77 

.80 

1.92 

.80 

4.24 

2.80 

6.57 

3.80 

8.89 

.85 

2.03 

.85 

4.35 

2.85 

6.68 

3.85 

9.00 

.90 

2.15 

.90 

4.47 

2.90 

6.80 

3.90 

9.12 

.95 

2.26 

.95 

4.59 

2.95 

6.91 

3.95 

9.24 

4.00 

9.36 

CURRENT  METERS  237 

ELECTRIC  CURRENT  METER,  OMITTING    VANE 
AND  LEAD    WEIGHT 

FOR   USE   IN   SHALLOW   STREAMS 


NO.  618 

Price,  complete,  $63.50 

A  modification  of  the  Electric  Current  Meter,  No.  617, 
is  shown  in  No.  618.  The  vane,  lead  weight,  and  suspending 
cable  are  omitted.  The  meter  is  mounted  on  a  base,  as 
shown,  and  is  provided  with  two  lengths  of  nickel -plated 
brass  tubing,  graduated  to  feet  and  tenths  up  to  four  feet,  and 
is  easily  held  in  position  with  the  base  resting  on  the  bed  of 
the  stream.  The  electric  sounder,  with  twenty  feet  of  cable, 
and  connections  are  the  same  as  those  used  with  the  meter 
No.  617.  The  instrument  and  its  smaller  accessories  are 
packed  in  a  wooden  box  with  lock  and  strap. 

The  Reduction  Table  on  page  236  is  intended  for  use 
with  this  meter. 


238 


CURRENT  METERS 


ELECTRIC  CURRENT  METER,    WITH    VANE  AND 
TORPEDO  LEAD    WEIGHT 

FOR    USE   IN   SMALL   STREAMS 


NO.  621 

Price,  complete,  as  shown,  $63.50 

We  illustrate  above  a  new  model  of  current  meter  similar 
in  form  to  No.  617,  but  modified  in  some  particulars,  the 
most  important  of  which  is  that  only  every  fifth  revolution  of 
the  wheel  is  indicated,  thus  facilitating  the  use  of  the  meter 
for  high  velocities,  when  it  would  be  difficult  to  note  each 
revolution  of  the  wheel. 

PRICE 

Electric  Current  Meter  No.  621,  with  vane,  torpedo  weight,  electric 
sounder  with  telephone  ear-piece  and  twenty  feet  of  cablev 
Meter  arranged  to  indicate  only  every  fifth  revolution  of  the 
wheel..  ..$63.50 


BO  YD  EN  HOOK-GAUGE 


239 


ft- 


NO. 

Price, 


629 


BO  YD  EN  HOOK-GAUGE 

This  instrument,  so  called  from  the  name  of 
its  inventor,  is  used  in  determining  the  depth  of 
water  flowing  over  weirs,  etc. 

As  shown  in  the  cut,  it  has  a  frame  of  wood, 
three  feet  long  and  four  inches  wide,  in  a  rectan- 
gular groove  of  which  is  made  to  slide  another 
piece  carrying  a  metallic  scale,  graduated  in  feet 
and  hundredths,  and  figured  from  zero  to  two 
feet  and  two -tenths,  as  shown. 

Connected  with  the  scale  is  a  brass  screw 
passing  through  a  socket,  fastened  to  another 
shorter  sliding  piece,  shown  in  cut,  which  can  be 
clamped  at  any  point  on  the  frame,  and  the 
scale  with  hook  moved  in  either  direction  by  the 
milled-head  nut. 

A  vernier  is  also  attached  to  the  frame,  mov- 
able under  the  screw  heads  which  secure  it,  in 
order  to  adjust  its  zero  to  correspond  with  the 
point  of  the  hook,  as  will  be  described  hereafter. 
The  vernier  reads  the  scale  to  thousandths  of  a 
foot. 

The  hook  is  of  brass  and  has  a  sharp  point, 
which,  when  raised  to  the  surface  of  the  water 


$25.00.  at  rest,  indicates  its  precise  level. 


TO    USE   THE  HOOK-GAUGE 

The  hook-gauge  is  used  in  a  box  attached  to  a  flume  at 
any  convenient  point  near  the  weir,  the  water  from  the  flume 
being  conveyed  to  the  box  by  rubber  or  lead  pipes,  thus  indi- 
cating the  precise  level  of  the  water  in  the  flume,  the  surface 
of  the  water  in  the  box  being  at  rest. 


240  BO  YD  EN  HOOK-GAUGE 

When  the  depth  of  the  water  passing  over  a  weir  is 
required,  the  exact  level  of  the  crest  of  the  weir  should  be 
taken  by  a  leveling-instrument  and  rod,  and  marked  by  a 
line  drawn  in  the  still-water  box  above  the  surface  of  the 
water.  The  scale  of  the  gauge  being  previously  set  at  zero 
with  the  vernier,  the  frame  is  fastened  to  the  box  above  the 
water  in  such  a  position  that  the  point  of  the  hook  is  at  the 
same  level  as  the  crest  of  the  weir,  the  precise  point  being 
secured  by  the  adjusting -screw  of  the  scale.  See  that  the 
zeros  of  the  scale  and  vernier  are  in  line,  and  if  not,  move 
the  vernier  under  the  screw  heads  until  the  zeros  correspond, 
and  set  the  vernier  fast.  The  point  of  the  hook  will,  of 
course,  be  under  water,  and  level  with  the  crest  of  the 
weir. 

The  depth  of  water  flowing  over  the  weir  is  the  distance 
between  the  point  of  the  hook  in  the  position  named  and  the 
exact  surface  of  the  water.  To  ascertain  this,  the  hook  is 
raised  by  turning  the  milled-head  nut  until  the  point  of  the 
hook,  appearing  a  little  above  the  surface,  causes  a  distortion 
in  the  reflection  of  the  light  from  the  surface  of  the  water. 
A  slight  movement  of  the  hook  in  the  opposite  direction  will 
cause  the  distortion  to  disappear,  and  will  indicate  the  surface 
with  precision.  The  reading  of  the  scale  will  then  give  the 
depth  of  water  passing  over  the  weir,  in  thousandths  of  a 
foot. 

It  will  be  understood  from  the  cut  that  the  longer  move- 
ments of  the  scale  are  made  by  moving  the  clamping  piece 
over  the  frame,  the  finer  adjustments  being  effected  by  the 
milled  nut. 

We  are  also  prepared  to  make  to  order,  from  designs  fur- 
nished, water  registers,  tide  gauges,  and  all  similar  instru- 
ments. 


HAND   LEVELS 
TELESCOPIC  HAND  LEVELS 


241 


NO. 640 

Price,  «12.00. 


NO.  641 

Price,  $15.00. 


The  figures  represent  instruments  devised  by  us  as  an 
improvement  upon  the  ordinary  hand  levels,  calculated  to 
increase  their  usefulness  in  the  work  of  the  engineer. 

The  Monocular  Hand  Level,  shown  in  No.  640,  consists 
of  a  tube  to  which  are  fitted  the  lenses  of  a  single  opera  glass, 
and  which  also  contains  a  reflecting  prism,  a  cross-wire,  and  a 
level -vial,  the  latter  being  seen  in  the  open  part  of  the  tube. 

The  eye  lens,  as  indicated  in  the  cut,  is  composed  of  two 
separate  pieces,  the  larger  one  being  the  usual  concave  eye 
lens  of  the  o'pera  glass,  and  the  smaller  a  segment  of  a  plano- 
convex lens  having  its  focus  on  a  cross-wire  under  the  level - 
vial  and  above  the  reflecting  prism. 

The  observer  holds  the  tube  horizontal  with  the  level- 
opening  uppermost,  and  observes  the  object  to  which  the 


242  HAND  LEVELS 

instrument  is  directed,  and  the  position  of  the  level-bubble 
with  reference  to  the  cross-wire  on  the  under  side  of  the  level - 
vial. 

When  the  hand  level  is  held  truly  horizontal  the  cross-wire 
will  bisect  the  bubble,  and  will  determine  the  level  of  any 
object  seen  through  the  telescope,  thus  securing  to  the 
observer  a  clear  view  of  the  object,  magnified  by  the  tele- 
scope. 

The  Binocular  Hand  Level,  shown  as  No.  641,  consists  of 
two  tubes,  the  one  on  the  right  enclosing  the  usual  lenses  of 
the  opera  glass,  and  the  tube  on  the  left  containing  only  the 
prism,  level -vial  and  cross-wire  of  the  instrument  just  described. 
This  level  is  used  like  the  ordinary  opera  glass,  being  held 
with  the  level -vial  above,  as  shown  in  the  cut. 

When  the  tubes  are  held  truly  horizontal,  the  engineer 
will  see  with  one  eye  the  cross-wire  bisecting  the  bubble,  and 
with  the  other  eye  will  see  the  object  observed,  the  level  line 
of  which  is  determined  by  the  position  of  the  cross -wire  upon 
•the  surface  of  the  level -vial. 

The  Binocular  Hand  Level  gives  a  clearer  view  of  an  object 
than  is  possible  with  a  single  tube,  there  being  no  light  lost  by 
the  interference  of  the  prism  and  the  level -vial. 

The  hand  level  is  adjusted  by  sliding  the  prism  tube  back 
and  forth,  until  the  line  given  is  the  same  as  that  given  by  a 
Y  Level. 

The  prism  in  the  tube  can  be  reached  by  removing  the 
cap  from  the  closed  end  of  the  tube,  and  it  is  clamped  by  a 
small  screw  on  the  lower  side. 


HAND   LEVELS 
LOCKE  HAND  LEVEL 


This  instrument  consists  of  a  brass  tube  about  six  inches 
long,  having  a  level-vial  on  top  and  near  the  object  end, 
as  shown  in  the  figure.  There  is  an  opening  in  the  tube 
beneath,  through  which  the  bubble  can  be  seen,  as  reflected 
by  a  prism  immediately  under  the  level-vial.  Both  ends  of 
the  tube  are  closed  by  disks  of  plain  glass  to  exclude  dust, 
and  there  is  at  the  inner  end  of  the  sliding  or  eye  tube  a  semi- 
circular convex  lens,  which  serves  to  magnify  the  level -bubble 
and  the  cross-wire  beneath,  while  it  allows  the  object  to  be 
clearly  seen  through  the  open  half  of  the  tube. 

The  cross-wire  is  fastened  to  a  frame  moving  under  the 
level -tube,  and  adjusted  to  its  place  by  the  small  screw  shown 
on  the  end  of  the  level -case.  The  level  of  any  object  in 
line  with  the  eye  of  the  observer  is  determined  by  sighting 
upon  it  through  the  tube,  and  bringing  the  bubble  of  the 
level  into  a  position  where  it  is  bisected  by  the  cross-wire. 


244  HAND   LEVELS 


ABNEY  LEVEL 
AND   CLINOMETER 

NO.   646 


The  Abney  Level  is  a  modification  of  the  Locke  Hand 
Level,  combining  with  it  an  excellent  clinometer,  as  shown  in 
the  cut. 

The  main  tube  being  square,  it  can  be  applied  to  any  sur- 
face, the  inclination  of  which  is  ascertained  by  bringing  the 
level-bubble  into  the  middle,  and  reading  off  the  angle  to  five 
minutes  by  the  arc  and  vernier.  When  sighted  at  an  object 
and  the  bubble  brought  into  the  middle,  the  vertical  angle 
from  the  height  of  the  eye  is  indicated.  When  at  zero  it 
would  indicate  a  level  line. 

The  inner  and  shorter  arc  indicates  the  lines  of  different 
degrees  of  slope,  the  left  edge  of  the  vernier  plate  being  ap- 
plied to  the  lines,  and  the  bubble  brought  into  the  middle  as 
usual.  A  small  compass,  with  needle  about  one  and  one-half 
inches  long,  is  sometimes  attached  to  the  upper  surface  of  the 
Abney  Level,  with  a  plain  staff  socket  below. 

PRICES 

No.  PRICE       POST. 

646  Abney  Level,  an  improved  Locke  Hand  Level,  giv- 
ing angles  of  elevation,  and  also  divided  for  slopes, 
as  1  to  1,  2  to  1,  etc. ;  in  case $13.50  $0.25 

648  Same  as  No.  646,  and  with  compass  and  plain  staff 

socket  attached 18,00  ,30 


CHAINS 


The  sizes  and  diameters  of  iron  and  steel  wire  commonly 
used  in  making  surveyors'   and  engineers' 

SIZES   OF  WIRE  ...  J     __  *    .       , 

chains  are  as  follows:  No.  8,  .162-inch; 
No.  10,  .135-inch;  No.  12,  .105-inch;  No.  15,  .072-inch; 
No.  18,  .047-inch. 

The  ordinary  Gunter's  or  surveyors'  chain  is  sixty -six  feet 
or  four  poles  long,  and  is  composed  of  one  hundred  links, 
LAND  SURVEYORS'      connected  each  to  each  by  two  rings, 
CHAINS  and   furnished   with    a   tally    mark    at 

the  end  of  every  ten  links.  A  link  in  measurement  includes 
a  ring  at  each  end,  and  is  seven  and  ninety -two  one-hundredths 
inches  long.  In  all  the  chains  which  we  make  the  rings  are 
oval  and  are  sawed  and  well  closed,  the  ends  of  the  wire  form- 
ing the  hook  being  also  filed  and  bent  close  to  the  link,  to 
avoid  kinking.  The  oval  rings  are  about  one -third  stronger 
than  round  ones. 

The  handles  are  of  brass  and  form  part  of  the 

HANDLES  ,  ..    . 

end  links,  to  which  they  are  connected  by  a  short 

link  and  jam -nuts,  by  which  the  length  of  the  chain  is  adjusted. 

The  tallies  are  of  brass,  and  have  one,  two,  three  or  four 

notches,  as  they  mark  ten,  twenty,  thirty  or  forty 

links  from  either  end.     The  fiftieth  link  is  marked 

by  a  rounded  tally  to  distinguish  it  from  the  others. 

In  place  of  the  four-pole  chain  just  described,  many  sur- 
veyors prefer  a  chain  two  rods  or  thirty-three 

MAI   F-f^MAlIM^ 

feet  long,  having  only  fifty  links,  which  are 
counted  by  tallies  from  one  end  in  a  single  direction. 

Our  surveyors'  chains  are  made  of  Nos.  8  and  10  refined 
245 


246  CHAINS 

iron  wire,  and  of  Nos.  8,  10,  12  and  15  best  steel  wire. 
IRON  AND  STEEL  Steel  chains  are  often  preferred  on 
WIRE  account  of  their  greater  strength,  although 

they  are  more  costly  than  those  of  iron. 

Engineers'  chains  differ  from  surveyors'  chains,  in  that 
ENGINEERS'  a  ^m^  including  a  ring  at  each  end  is  one  foot 
CHAINS  long,  and  the  wire  is  of  steel  and  therefore 
much  stronger. 

They  are  either  fifty  or  one  hundred  feet  long,  and  are 
furnished  with  swivel  handles  and  tallies  like  those  just 
described.  The  wire  used  for  these  chains  is  of  steel  of  the 
first  quality,  Nos.  8,  10  and  12. 

A  very  light  and  strong  chain  is  made  of  No.  12  steel 
BRAZED  STEEL  wire,  the  links  and  rings  of  which  are 

CHAINS  securely  brazed.  The  wire  is  of  a  low 

spring-temper,  and  the  chain,  though  light,  is  almost  in- 
capable of  being  broken  or  stretched  in  careful  use. 

Our  brazed  steel  chains  have  been  found  exceedingly  de- 
sirable for  all  kinds  of  measurement,  and  for  the  use  of 
engineers  upon  railroads  and  canals  they  have  very  generally 
superseded  the  heavier  chains. 

We  frequently  make  chains  with  steel  snaps  in  the  middle 
and  at  one  handle.  The  chain  can  then  be 

STEEL  SNAPS  ,         ,,       ,     .  , 

separated,  and  one  handle  being  removed 
and  transferred  to  the  forty-ninth  link,  a  chain  of  half  length 
is  obtained.  This  modification  is  made  without  charge,  if 
ordered  with  the  chain. 

In  using  the  chain  the  length  must  be  taken  from  the 
TO  USE  THE  extreme  ends,  and  the  marking-pins  placed  on 

CHAIN  the  outside  of  the  handles.  It  must  be  drawn 

straight  and  taut,  and  carefully  examined  to  detect  any  kinks 
Or  other  causes  of  inaccuracy. 


CHAINS  247 

Our  chains  are  carefully  tested  at  every  link  and  in  their 
whole  length,  by  the  U.  S.  standard, 
with  a  strain  of  ten  pounds  and  with 

temperature  at  62°  Fahrenheit;  and  when  new  they  may 
always  be  relied  upon  as  correct. 

All  chains  will  be  more  or  less  lengthened  after  long  use 
in  the  field,  and  it  will  be  best  for  the  surveyor  to  lay  down 
on  a  level  surface  the  exact  length  of  the  chain  when  new, 
marking  its  extreme  ends  by  monuments  which  will  not  be 
liable  to  disturbance.  He  will  thus  have  a  standard  measure  ^ 
of  his  own  to  which  the  chain  can  be  adjusted  from  time  to 
time. 

GRUMMAN'S  PATENT  CHAINS 

• 
These  chains,  invented  and  patented  by  J.  M.  Grumman, 

of  Brooklyn,  N.  Y.,  are  made  of  very  light  steel  wire,  the 
links  being  finely  tempered,  and,  as  shown  in  the  cut,  so 
formed  at  the  ends  as  to  fold  together  readily,  and  thus 
dispense  with  the  use  of  rings. 


This  construction  gives  but  one -third  as  many  wearing 
points  as  are  in  the  ordinary  chain,  and  affords  the  utmost 
facility  for  repairs. 

Five  or  ten  extra  links  are  furnished  with  each  chain,  and 
these  have  only  to  be  sprung  into  place  to  replace  any  which 
may  have  been  broken.  The  chain  can  also  be  sprung  apart 
at  any  link,  and  be  made  of  any  length  desired. 

Some  of  these  chains  are  made  of  No.  15  wire,  and  are 


248  CHAINS 

used  for  measuring  on  the  surface,  like  the  ordinary  chain. 
One  is  used  as  a  suspended  chain  for  very  accurate  measure- 
ments, and  is  of  No.  18  wire  and  provided  with  spring-balance, 
level  and  thermometer  attachments.  When  in  use  it  is  held 
above  the  surface,  and  the  extremities  of  the  chain  are  marked 
upon  the  ground  by  the  points  of  plummets  let  fall  from  fixed 
places  on  the  chain. 

VARA    CHAINS 

The  vara,  which  is  in  general  use  in  Texas,  is  33.333 
inches  long.  The  chains  are  made  both  of  iron  and  steel 
wire,  ten  or  twenty  varas  in  length,  each  vara  being  usually 
divided  into  five  links.  A  link,  including  a  ring  at  each 
end,  is  therefore  6.666  inches  long.  A  ten -vara  chain  has 
fifty  links,  a  twenty-vara  chain  one  hundred  links.  Each 
vara  is  marked  by  a  round  brass  tally,  numbered  from  one  to 
nine  in  the  ten-vara  chain,  and  from  one  to  nineteen  in  the 
twenty-vara  chain. 

METER  CHAINS 

The  meter  is  used  as  a  standard  measure  of  length  in  many 
countries,  and  chains  of  ten  and  twenty  meters  are  often 
ordered.  The  chains  are  made  of  iron  or  steel  wire,  each 
meter  being  divided  into  five  links.  As  a  meter  is  39.371 
inches  long,  a  link,  including  a  ring  at  each  end,  measures 
7.874  inches. 

A  ten -meter  chain  has  fifty  links  and  a  twenty -meter  chain 
one  hundred  links.  Each  meter  is  marked  with  a  round  brass 
tally  numbered  from  one  to  nine  in  the  ten-meter  chain,  and 
from  one  to  nineteen  in  the  twenty -meter  chain. 


TAPES  249 

MARKING-PINS 

In  chaining,  eleven  marking-pins  are  needed,  made  either 
of  iron,  steel  or  brass  wire,  as  .preferred.  They  are  about 
fourteen  inches  long,  pointed  at  one  end  to  enter  the  ground, 
and  formed  into  a  ring  at  the  other  end  for  convenience  in 
handling. 

Marking-pins  are  sometimes  loaded  with  a  little  mass  of 
lead  around  the  lower  end,  to  serve  as  a  plumb  when  the  pin 
is  dropped  to  the  ground  from  the  suspended  end  of  the 
chain. 

CHAIN   TAPES 

Chain  tapes  are  generally  used  on  bridge,  road  and  street 
work,  and  as  standards  for  comparison  of  other  chains  and 
tapes.  They  are  made  of  a  thin  ribbon  of  steel  about  one- 
quarter  of  an  inch  wide,  and  of  straight  spring-temper,  and 
commonly  in  lengths  of  from  thirty -three  to  five  hundred  feet. 

The  thirty-three  and  sixty-six  feet  lengths  are  usually 
graduated  at  each  Gunter's  link  for  use  in  land  surveying, 
and  the  fifty  and  one  hundred -feet  lengths  are  graduated  at 
each  foot,  and  also  have  the  first  and  last  foot  marked  in 
tenths,  for  city  work.  See  Nos.  760  to  768  of  the  Price 
List. 


NO.  760 


A  convenient  reel  for  these  tapes  is  shown  in  -the  cut. 
When  not  in  use  the  handle  of  the  drum  can  be  folded  flat, 
and  a  small  projection  at  its  base  fits  into  a  slot  made  to 


250  TAPES 

receive  it,  and  thus  clamps  the  drum  and  prevents  the  tape 
from  unwinding. 


NO.  77O 

The  tapes  from  three  hundred  to  five  hundred  feet  in 
length  are  usually  graduated  at  each  five  feet,  with  the  first 
and  last  five  feet  marked  at  each  foot.  They  are  wound 
upon  a  substantial  wooden  reel  with  aluminum  and  brass 
mountings,  as  shown  above.  See  Nos.  770  to  772  of  the 
Price  List. 

Our  chain  tapes  are  U.  S.  standard  measure  at  62° 
Fahrenheit,  and  with  ten  pounds  strain. 

METALLIC   TAPES 

These  are  of  linen,  about  five-eighths  of  an  inch  wide, 
and  have  fine  brass  wires  interwoven  through  their  whole 
length.  They  are  thus  measurably  correct,  even  when  wet. 

They  are  graduated  in  feet  and  tenths  or  in  feet  and 
inches,  on  one  side,  as  ordered,  and  are  marked  in  links  on 
the  reverse  side.  They  are  wound  in  a  leather  case  having  a 
folding  handle.  See  Nos.  780  to  794  of  the  Price  List. 

STEEL    TAPES 

The  best  tapes  are  made  of  a  thin  ribbon  of  steel  in  one 
piece,  of  straight  spring-temper,  and  either  one-quarter,  three- 
eighths  or  one-half  inch  wide. 

They  are  made  in  all  lengths  from  twenty-five  to  one  hun- 


TAPES  251 

dred  feet,  graduated  to  feet  and  inches,  with  links  on  the 
reverse  side,  or  more  usually  feet  and  tenths  of  a  foot,  with 
links  on  the  reverse  side,  the  figures  and  graduations  being 
etched  on  the  surface  of  the  steel. 

American  steel  tapes  ( Paine' s  pattern)  are  made  of  thin 
steel  ribbon  in  one  piece,  about  one-quarter  of  an  inch  wide 
and  of  straight  spring-temper.  They  can  be  detached  from 
the  case  when  desired,  and  used  with  a  pair  of  handles  with 
compensation  scale  for  variations  of  temperature,  for  chain 
measurements. 

These  tapes  are  U.  S.  standard  measure  at  62°  Fahren- 
heit, with  about  twelve  pounds  strain.  A  hundred-foot  tape 
expands  .0756  inch  for  each  10°  rise  in  temperature. 

The  tapes  are  wound  in  a  leather  or  metal  case  with  fold- 
ing handle.  See  Nos.  800  to  835  of  the  Price  List. 

Our  Excelsior  steel  tape  is  well  liked  for  use  in  mines.  It 
is  one-half  inch  wide,  and  is  mounted  on  an  open  brass  frame 
with  folding  handle.  The  tape  is  easily  wound  and  unwound, 
and  the  open  frame  allows  the  evaporation  of  moisture.  See 
Nos.  850  to  859B  of  the  Price  List. 

METRIC  AND    VARA    TAPES 

We  can  furnish  any  of  our  metallic  tapes,  Nos.  780  to 
794,  and  steel  tapes,  Nos.  820  to  835,  with  metric  or  vara 
measure  on  the  reverse  side  instead  of  links,  at  extra  prices, 
as  quoted  on  pages  294  and  29i6 ;  and  with  metric  or  vara 
measure  only,  at  prices  of  regular  styles  of  the  same  length  in 
feet.  Our  chain  tapes,  Nos.  760  to  772,  are  also  graduated 
with  metric  measure  only,  when  so  ordered,  and  are  marked 
at  each  meter,  with  the  first  and  last  meter  in  decimeters. 
If  graduated  with  vara  measure  only,  they  are  marked  at 
each  vara,  with  the  first  and  last  vara  in  tenths. 


INFORMATION  TO  PURCHASERS 


SELECTION  OF  INSTRUMENTS 
PLAIN  COMPASS  will  answer  for  original  surveys,  or 
for  ascertaining  the  bearing  of  lines  in  the  preparation 
of  county  maps. 

The  VERNIER  COMPASS,  or  VERNIER  TRANSIT  COMPASS, 
will  be  required  where  allowance  must  be  made  for  the 
magnetic  declination,  as  in  retracing  the  lines  of  an  old 
survey. 

When  local  attraction  must  be  taken  into  account,  in 
addition  to  the  magnetic  declination,  and  angles  must  be 
taken  independently  of  the  needle,  an  instrument  with  a 
graduated  limb  must  be  used,  and  for  this  purpose  the  RAIL- 
ROAD COMPASS  will  be  suitable. 

For  a  mixed  practice  of  general  surveying,  including 
farm  and  city  work,  the  establishment  of  grades  and  the 
running  of  levels,  such  an  instrument  as  the  SUR- 
VEYORS' TRANSIT,  with  its  various  attachments,  is  amply 
sufficient. 

The  different  forms  of  the  ENGINEERS'  TRANSIT,  the 
MOUNTAIN  TRANSIT,  and  the  Y  LEVELING  INSTRUMENTS  are 
designed  for  engineering  work  of  the  highest  class. 

In  the  United  States  public  land  surveys,  an  instrument 
with  solar  attachment  is  required,  and  the  SOLAR  TRANSIT  is 
usually  selected. 

In  surveys  of  mining  claims,  especially  in  locations 
difficult  of  access,  and  for  the  survey  of  mines  in  general, 
the  MOUNTAIN  TRANSIT,  with  the  solar  attachment  and 
other  attachments,  has  proved  a  universal  favorite. 

253 


254  INFORMATION  TO   PURCHASERS 

The  various  PLANE-TABLE  outfits  have  a  recognized 
utility  for  topographical  work  and  map  drawing. 

The  CURRENT  METERS  are  almost  indispensable  in  meas- 
uring the  velocity  of  the  flow  of  water  in  harbors,  rivers, 
small  streams  and  irrigation  ditches. 

The  DRAINAGE  LEVEL  is  the  simplest  and  most  efficient 
instrument  designed  for  laying  out  drains  and  similar  work. 

The  ARCHITECTS'  LEVEL  and  the  BUILDERS'  TRANSIT  are 
used  in  laying  out  buildings,  determining  the  level  of  their 
floors,  sills  and  windows,  and  in  the  general  work  of  the 
builder. 

The  EXPLORERS'  TRANSIT,  the  RECONNOISSANCE  TRANSIT 
and  the  various  forms  of  POCKET  COMPASSES,  with  or  with- 
out telescopic  attachment,  are  very  desirable  for  a  large 
class  of  work  where  extreme  lightness  and  portability  are 
desirable. 

Where  iron  ores  are  to  be  traced,  the  MINERS'  Dip-CoM- 
PASS,  the  DIAL  COMPASS  and  the  POCKET  SOLAR  COMPASS  are 
used.  We  do  not  make  any  instrument  by  which  veins  of 
gold  and  silver  can  be  traced,  or  the  presence  of  these 
metals  detected. 

LOW  PRICE  OF  OUR  INSTRUMENTS 

It  is  often  stated  that  it  is  impossible  to  make  first-class 
instruments  at  our  prices,  which  are  much  lower  than  those 
of  other  skillful  manufacturers.  To  this  we  can  only  reply 
that  a  visit  to  our  works,  and  a  comparison  of  our  facilities 
with  those  of  any  other  manufacturer  will  dispel  all  doubts  as 
to  our  ability  to  furnish  the  best  instruments  for  the  money 
that  can  be  produced  in  this  country. 

Our  instruments  are  not  carried  in  stock  by  merchants, 
and  we  do  not  deem  it  advisable  to  add  to  our  prices  in  order 


INFORMATION  TO   PURCHASERS  255 

to  enable  us  to  give  to  merchants  a  large  discount,  which,  of 
course,  would  be  paid  by  the  purchaser. 

TERMS  OF  PAYMENT 

Our  terms  of  payment  are  uniformly  cash  and  we  have  but 
one  price,  whether  ordered  in  person  or  by  mail  or  telegraph. 
Our  prices  are  as  low  as  can  be  made  for  instruments  of  first 
quality. 

Remittances  may  be  made  by  a  cashier's  draft  payable  to 
our  order,  which  can  be  procured  from  banks  or  bankers  in 
almost  all  the  larger  villages,  or  by  express  company  or  post- 
office  money  orders.  These  may  be  sent  by  mail  with  the 
order  for  the  instrument,  and  if  lost  or  stolen  on  the  way 
can  be  replaced  by  a  duplicate  obtained  as  before,  without 
additional  cost.  The  customer  may  also  send  the  money  in 
advance  by  registered  mail  or  by  the  express  agent,  or  may 
pay  the  agent  on  receipt  of  the  instrument  in  funds  current  in 
New  York. 

The  cost  of  returning  the  money  on  bills  amounting  to 
less  than  $20,  collected  by  express,  will  be  charged  to  the 
customer. 

When  articles  are  to  be  sent  by  mail  payment  must  be 
made  in  advance,  including  the  cost  of  postage.  The  postage 
required  is  mentioned  in  the  second  column  of  the  Price  List. 

Customers  ordering  instruments  and  desiring  changes  in 
construction  from  our  regular  patterns  must  make  a  payment 
in  advance,  with  the  order,  of  fifty  per  cent,  of  the  price. 

WARRANTY 

All  our  instrument  are  very  critically  tested  before  ship- 
ment, and  are  sent  to  the  purchaser  adjusted  and  ready  for 
immediate  use. 

When  purchased  directly  from  us  they  are  warranted  cor- 


256  INFORMATION  TO   PURCHASERS 

rect  in  all  their  parts,  we  agreeing,  in  the  event  of  any  defect 
appearing  after  reasonable  use,  to  repair  or  replace  with  a 
new  and  perfect  instrument,  promptly,  and  at  our  own  cost, 
express  charges  included ;  or  we  will  refund  the  money  and 
the  express  charges  paid  by  the  customer. 

It  will  sometimes  happen,  in  a  business  as  large  and  widely 
extended  as  ours,  that  instruments  reach  our  customers  in  bad 
condition,  owing  to  careless  transportation  or  to  defects  escap- 
ing the  closest  scrutiny  of  the  maker.  We  consider  the  reten- 
tion of  such  instruments  by  the  purchaser  an  injury  very  much 
greater  to  us  than  to  himself. 

TRIAL   OF   INSTRUMENTS 

This  statement  may  be  read  by  those  who  are  entirely 
unacquainted  with  us  or  the  quality  of  our  work,  and  who 
therefore  feel  unwilling  to  purchase  an  instrument,  of  the 
excellence  of  which  they  are  not  perfectly  assured. 

To  such  persons  we  make  the  following  proposition :  If 
requested  to  do  so,  we  will  send  the  instrument  to  the  express 
station  nearest  the  purchaser,  and  direct  the  express  agent  to 
collect  our  bill  on  delivery,  together  with  charges  for  trans- 
portation, and  hold  the  money  on  deposit  three  days,  if 
desired,  until  the  purchaser  shall  have  had  an  actual  trial  of 
the  instrument. 

If  the  instrument  is  not  found  as  represented,  the  pur- 
chaser may  return  it  before  the  expiration  of  the  specified 
time,  and  receive  in  full  the  money  paid  the  agent,  including 
express  charges,  and  direct  the  instrument  to  be  returned 
to  us. 

This  privilege  of  trial  applies  only  to  our  larger  transits, 
levels,  and  compasses,  is  not  given  unless  requested,  and  is 
allowed  only  in  the  United  States. 


INFORMATION  TO   PURCHASERS  257 

EXTENT  OF  OUR  PLANT 

For  many  years  our  facilities  for  manufacturing  have  been 
far  superior  to  those  of  any  other  similar  establishment  in  the 
world,  and  they  are  being  constantly  increased  by  the  intro- 
duction of  new  machinery  and  tools. 

We  now  make  under  our  own  roof  the  lenses  for  the 
telescopes  of  our  instruments,  the  glass  vials  for  the  level - 
tubes,  the  wooden  boxes  in  which  the  instruments  are  packed, 
and  the  leather  cases  and  straps  for  these  boxes,  as  well  as  all 
the  metal  parts  of  the  instruments  themselves. 

FINISH  OF  INSTRUMENTS 

All  instruments  are  covered  with  a  lacquer  applied  while 
the  work  is  heated.  As  long  as  this  lacquer  remains  the 
brass  surface  will  not  tarnish,  and  the  engineer  can  preserve 
its  original  freshness  for  a  long  time  by  taking  care  not  to 
rub  the  instrument  with  a  dusty  cloth  or  expose  it  to  the 
friction  of  his  clothes. 

Instead  of  the  brass  finish,  most  engineers  prefer  instru- 
ments blackened  or  bronzed.  This  is  done  with  an  acid 
preparation,  after  the  work  has  been  polished,  and  gives  the 
instrument  a  very  showy  appearance.  It  is  also  advantageous 
because  it  does  not  reflect  the  rays  of  the  sun  as  much  as  the 
bright  or  brass  finish. 

If  no  special  direction  is  given,  we  usually  send  transits, 
levels,  and  solar  instruments  with  bronze  finish,  and  com- 
passes with  bright  finish. 

ALUMINUM 

Since  1876  we  have  made  civil  engineers'  and  surveyors' 
instruments  of  aluminum,  to  order  only.  The  sole  advantage 
which  instruments  of  aluminum  have  over  those  of  the 


258  INFORMATION   TO   PURCHASERS 

ordinary  metals  is  their  light  weight ;  but  as  all  the  bearing 
parts  must  be  made  of  bronze,  the  total  weight  can  be  reduced 
only  about  fifty  per  cent.  We  finish  our  aluminum  instru- 
ments in  the  natural  color,  and  the  result  is  more  satisfactory 
than  when  an  artificial  coloring  is  used,  although  it  entails 
much  extra  expense  upon  the  manufacturer.  We  will  quote 
prices  on  application  for  any  of  our  instruments  of  regular 
pattern  made  of  aluminum. 

PACKING 

Each  of  our  transits,  levels,  and  surveyors'  compasses  is 
packed  in  a  well -finished  mahogany  case,  furnished  with  lock 
and  key  and  brass  hooks,  and  leather  strap  for  convenience 
in  carrying.  Each  case  is  provided  with  screw-driver,  ad- 
justing-pin and  wrench  for  center-pin,  and,  if  accompanied 
by  a  tripod,  with  a  brass  plummet.  With  all  the  instruments 
used  for  taking  angles  without  the  needle,  a  reading-glass  is 
also  furnished. 

Unless  the  purchaser  is  already  supplied,  each  instrument 
is  accompanied  by  our  Manual,  giving  full  instruction  for 
such  adjustments  and  repairs  as  are  possible  to  one  not  pro- 
vided with  the  facilities  of  an  instrument-maker. 

When  sent  to  the  purchaser,  the  mahogany  cases  are  en- 
closed in  outside  packing-boxes  of  pine,  made  a  little  larger 
on  all  sides  to  allow  the  introduction  of  elastic  material.  So 
effectually  are  our  instruments  protected  by  these  precautions, 
that  of  very  many  thousands  sent  out  since  1846,  in  all  sea- 
sons and  by  every  mode  of  transportation,  and  to  all  parts  of 
the  world,  very  few  have  sustained  any  serious  injury. 

Instruments  packed  for  foreign  shipment,  which  are  to 
have  ocean  passage,  are  hermetically  sealed  in  tin  cases. 


INFORMATION  TO   PURCHASERS  259 

MEANS  OF    TRANSPORTATION 
.Instruments  can  be  sent  by  express  to  almost  every  town 
in    the    United    States,   Canada  -and    Mexico,   agents   being 
located  at  all  the  more  important  points,  by  whom  they  are 
forwarded  to  smaller  places  by  stage. 

Charges  for  transportation  are  in  all  cases  to  be  borne  by 
the  purchaser,  we  guaranteeing  the  safe  arrival  of  our  instru- 
ments at  his  express  office,  and  holding  the  express  company 
responsible  for  loss  and  damage  on  the  way. 

INSTRUMENTS  FOR  FOREIGN  COUNTRIES 

We  send  civil  engineers'  and  surveyors'  instruments  to 
Canada,  Mexico,  Central  America,  Cuba,  South  America, 
China,  Japan,  Australia,  Africa  and  India,  as  well  as  to 
various  parts  of  Europe. 

In  every  case,  the  cash  for  orders  for  foreign  shipments  by 
steamship  must  accompany  the  order.  If  it  is  desired  that  we 
attend  to  the  shipment  of  the  instruments,  the  remittance 
must  be  made  ten  per  cent,  more  than  the  catalogue  price  of 
the  instruments  if  the  order  amounts  to  $250  or  less,  eight 
per  cent,  more  than  the  catalogue  price  if  the  order  amounts 
to  from  $300  to  $500,  or  six  per  cent,  more  than  the  cata- 
logue price  if  the  order  amounts  to  from  $600  to  $1,000. 
The  extra  remittance  is  to  cover  the  cost  of  shipping  charges, 
freight  and  insurance,  which  must  always  be  paid  in  advance 
on  all  shipments  except  those  to  Canada  and  some  parts  of 
Mexico. 

If  the  amount  remitted  is  more  than  sufficient  to  cover 
these  expenses,  any  balance  will  be  returned  to  the  purchaser 
with  the  receipted  bill  and  bill  of  lading,  unless  we  are 
directed  to  hold  it  to  his  credit  and  subject  to  his  order. 

Remittances  must  be  made  by  bankers'  draft  on  London, 


260  INFORMATION  TO  PURCHASERS 

England,  or  on  New  York  city,  and  such  drafts  can  be  pur- 
chased in  any  of  the  large  cities  of  the  countries  named  above. 
When  telegraphing  cable  messages  to  us,  use  either  the 
Western  Union  or  the  Lieber  code. 

REPAIR   OF  INSTRUMENTS 

We  receive  every  year  more  than  a  thousand  instruments 
of  our  own  and  others'  make,  sent  to  us  for  refitting  and 
repairs.  Most  of  these  have  been  injured  by  falls,  many  have 
parts  worn  and  defective  after  long  use,  and  others  are  sent 
for  repolishing  and  renovating. 

The  injuries  are  usually  more  serious  than  is  apparent  to 
the  owner,  and  their  full  extent  can  be  ascertained  only  by 
an  examination  as  the  instrument  is  taken  apart. 

We  advise  our  customers  who  have  instruments  in  need  of 
repairs  to  send  them  directly  to  us,  as  our  facilities  enable  us 
to  do  the  work  much  more  economically  and  promptly  than 
any  other  maker,  however  accessible. 

The  instruments  should  always,  when  practicable,  be 
placed  in  their  own  boxes,  and  then  enclosed  in  an  outside 
packing  case,  an  inch  larger  in  all  its  dimensions,  that  the 
space  between  the  two  may  be  filled  with  paper  wadding, 
hay  or  fine  shavings.  THE  OWNER'S  NAME  AND  ADDRESS 
should  always  appear  on  the  package,  and  a  note  specifying 
the  repairs  needed  should  always  accompany  the  instrument, 
and  a  letter  should  also  be  sent  to  us  by  mail,  giving  not  only 
directions  as  to  the  repairs,  but  also  stating  when  the  return  of 
the  instrument  is  desired  and  the  address  to  which  it  should 
be  forwarded. 

Each  instrument  is  made  to  fit  its  own  spindle,  and  no 
other  ;  and  therefore  this  part,  with  the  leveling-head,  if  it 
has  one,  should  always  be  sent  with  the  instrument.  The 


INFORMATION   TO   PURCHASERS  261 

tripod  legs  and  the  head  in  which  they  are  inserted  need  not 
be  sent,  unless  themselves  in  need  of  repairs. 

When  requested  to  do  so,  we  will  send  an  estimate  of  the 
cost  of  repairs  to  any  instrument  sent  us,  before  beginning 
the  work. 

Compasses  come  to  us  with  the  plates  sprung,  the  sights 
REPAIRS  TO  bent  or  broken,  the  glass  or  level-vials  frac- 
COM PASSES  tured,  and  the  pivot  so  dulled  as  to  render  the 
needle  sluggish  and  unreliable. 

The  cost  of  repairing  these  defects  ranges  from  $2  to  $10. 
A  pair  of  new  sights  fitted  costs  $5;  a  new  needle  with 
jeweled  center  and  pivot  complete,  $3  ;  a  new  jeweled  center 
only,  $1.50;  regraduating  the  compass  circle,  $5.  In  case 
of  any  trouble  with  the  needle  it  is  always  best  to  send  the 
needle  and  center-pin  to  us  by  mail,  with  $3.10,  and  we  will 
then  either  repair  and  return  the  parts,  with  any  balance  due  the 
owner,  or  we  can  send  new  needle  and  center-pin  complete, 
by  registered  mail  postpaid.  We  are  in  daily  receipt  of  com- 
pass needles  sent  to  us  for  repairs  from  all  parts  of  the  country. 

A  compass  sent  for  repairs  should  always  be  accompanied 
by  the  ball-spindle ;  and  if  a  new  ball-spindle  is  required, 
the  whole  instrument,  or  at  least  the  socket  in  which  the 
spindle  fits,  should  be  forwarded  to  us.  A  new  ball-spindle, 
fitted,  costs  $3.  See  also  page  264. 

Repairs  to  Railroad  Compasses  cost  from  $10  to  $20,  and 
to  Solar  Compasses  from  $20  to  $50.  Regraduating  the 
horizontal  limb  and  vernier  to  read  to  one  minute  costs  $10. 

The    injuries   which   Engineers'   and  Surveyors'   Transits 

sustain  by  falls  are  usually  much  more  serious.     The  plates, 

REPAIRS  TO      standards  and  cross-bars  of  telescopes  are  often 

TRANSITS       bent,  and  sockets  or  centers  are  generally  so 

deranged  as  to  be  entirely  useless. 


262  INFORMATION   TO   PURCHASERS 

The  cost  of  repairing  an  instrument  with  such  injuries 
ranges  from  $10  to  $30  or  even  $50,  new  sockets  alone 
costing  from  $15*  to  $20.  See  also  page  264. 

Variation  plate  added  to  an  Engineers'  Transit  sent 

for  repairs,  costs $15.00 

Regraduating  horizontal  limb  and  vernier  to  read  to 

one  minute,  costs 10.00 

Regraduating  vertical  limb  and  vernier  to  read  to  one 

minute,  costs 5.00 

No  one  but  a  skilled  workman  provided  with  the  best 
facilities  can  properly  set  the  platinum  wires  in  a  cross-wire 
PLATINUM  diaphragm,  and  it  is,  therefore,  useless  for 
CROSS-WIRES  us  to  send  a  parcel  of  wires  for  that  pur- 
pose. The  only  way  in  which  they  can  be  replaced  without 
sending  the  telescope  to  us  is  to  take  out  the  ring  and  send  it, 
with  its  screws,  washers,  etc.,  and  we  will  return  it  with  the 
wires  properly  secured. 


Plain  platinum  cross-wires,  replaced  on  the  old  ring, 

cost $2.00 

Adjustable  platinum  stadia  wires,  replaced  on  the  old 

ring,  cost 8.00 

Fixed  platinum  stadia  wires,  replaced  on  the  old  ring, 

cost. .  5.00 


If  to  be  sent  by  mail,  add  15  cents  for  postage  and  regis- 
try, and  25  cents  for  a  safety  brass  packing-box. 

We  are  not  responsible  for  wires  sent  in  this  way  and 
broken  while  inserting  the  ring  in  the  telescope.  The  best 
plan  is  to  send  us  the  telescope  when  new  cross-wires  are 
needed. 

When  it  is  desirable  to  substitute  platinum  for  spider- 
web,  a  new  ring  with  screws  will  be  required,  and  the  tele- 
scope should  be  sent  to  us. 


INFORMATION  -TO   PURCHASERS  263 

Plain  platinum  cross- wires,  with  diaphragm,  screws, 

etc.,  cost ». $3.00 

Adjustable   platinum   stadia  wires,  with   diaphragm, 

screws,  etc.,   cost . . .; 5.00 

Fixed  platinum  stadia  wires,  with  diaphragm,  screws, 

etc.,  cost 7.00 

See  also  pages  8  to  10. 

Leveling-instruments  are  generally  much  less  injured  by 
REPAIRS  TO      fe^  tnan  transits.     The  damages  usually  con- 
LEVELS          sist  in  the  bending  of  the  bar,  the  springing  of 
the  sockets,  and  the  breaking  of  the  vial. 

The  cost  of  repairs  varies  from  $5  to  $20.     A  new  level  - 
vial  set  in  the  old  tube  costs  $1.25  to  $2.50,  according  to 
the  size  of  the  level.     See  also  page  265. 
REPOLISHING  The  cost  of  repolishing   an    instrument 

INSTRUMENTS      varies,  but  may  be  stated  generally  as  fol- 
lows : 

COMPASSES,  Plain  and  Vernier $  5.00  to  $  7.00 

RAILROAD  COMPASSES 8.00  to    10.00 

SOLAR  COMPASSES,  large  size 12.00  to    15.00 

'  TRANSITS 12.00  to    15.00 

Y  LEVELS 8.00  to    12.00 

These  prices  are  in  addition  to  the  cost  of  adjustment  and 
of  any  necessary  repairs.  No  additional  charge  is  made  for 
bronzing  or  blackening  an  instrument  when  repolished. 

Payment  for  repairs  may  be  made  at  the  express  office 
where  the  instrument  is  received,  the  customer 

PAYMENT  .  .        - 

paying  in  advance  for  the  transportation  of  the 
instrument  to  us  or  not,  as  he  may  prefer.  Whenever  the 
charges  are  paid  in  advance,  the  express  receipt  should  be 
mailed  directly  to  us. 


264  INFORMATION  TO  PURCHASERS 

PRICES  FQR   PARTS  OF   INSTRUMENTS 
LIABLE  TO   LOSS   OR    INJURY 

FOR  TRANSITS 

PRICE  POST. 

Needle  with  jeweled  center  and  center-pin $3.00  $0. 10 

Center-pin  only : 50  .01 

Ground  glass  level-vial  for  plate  or  standard,  each 35  .02 

Ground   glass   level-vial,  brass   mounted  complete,  for  plate 

or  standard,  each 2.00  . 12 

Ground  glass  level-vial  for  telescope 1.25  .12 

Cap  for  eyepiece  or  objective,  each 75  .03 

Shade  for  objective 75  .03 

Clamp  screw  for  horizontal  limb 75  .02 

Tangent  screw  for  leveling-head 75  to  1.50  .11 

Clamp  screw  for  leveling-head 76  .03 

Leveling-screw  for  leveling-head 1.00  to  1.60  .12 

Eyepiece  complete 6.00  .12 

Objective  complete 6.00  .12 

Platinum  cross-wires  and  diaphragm 3.00  .15 

Platinum  stadia  wires,  adjustable,  and  diaphragm 5.00  .15 

Platinum  stadia  wires,  fixed,  and  diaphragm 7.00  .15 

Mahogany  box  with  lock  and  strap,  and  fitted  inside $5  to  $6 

FOR   SURVEYORS'    COMPASSES 

Needle  with  jeweled  center  and  center-pin $3.00  $0.10 

Center-pin  only 50  .01 

Ground  glass  level-vials,  each 35  .02 

Ground  glass  level-vials,  brass  mounted  complete,  each 2.00  .12 

Brass  cover  for  Compass  of  our  make 1.00  .25 

Outkeeper 1.00  .11 

Glass  circle  for  compass  face 25  .15 

Wrench  for  center-pin 10  .01 

Staff  mountings,  brass  head,  without  spindle 2.00  .25 

Staff  mountings,  steel  point.  .  . . 50  .18 

Ball-spindle,  fitted  to  old  socket 3.00  .30 

Compass  sight  vanes,  each 2.50  .20 

Clamp  screw  for  spindle  or  sight  vane 50  .03 

Tangent  screw  for  moving  vernier 1.5C  .10 

Staff  mountings  complete  for  Pocket  Compass,  small 2.50  .15 

Staff  mountings  complete  for  Pocket  Compass,  large 3.50  .20 

Mahogany  box  with  lock  and  strap,  and  fitted  inside $4  to  $6 


INFORMATION  TO  PURCHASERS  265 

PRICES   FOR   PARTS    OF   INSTRUMENTS 

FOR   Y   LEVELS 

PRICE  POST. 

Ground  glass  level-vial,  unmounted,  for  22-inch  Y  Level.  . .  .$1.85  $0.15 

Ground  glass  level-vial,  unmounted,  for  15-20-inch  Y  Levels.   1.65  .15 
Ground  glass  level-vial,  extra  sensitive   (ten  seconds  in  one- 
tenth  of  one  inch),  unmounted,  for  18-,  20-,  or  22-inch 

Y  levels .  4.00  .15 

Ground  glass  level- vial,  unmounted,  for  Architects'  Level  ...     .90  .05 

Cap  for  eyepiece  or  objective,  each 75  .03 

Clamp  screw  for  leveling-head 75  .03 

Tangent  screw  for  leveling-head 75  to  1 . 50  .11 

Leveling-screw  for  leveling-head,  each LOO  to  1.50  .12 

Eyepiece  complete 6.00  .12 

Objective  complete 7.00  .12 

Platinum  cross- wires  and  diaphragm 3.00  .15 

Platinum  stadia  wires,  adjustable,  and  diaphragm 5.00  .15 

Platinum  stadia  wires,  fixed,  and  diaphragm 7.00  .15 

Mahogany  box,  with  lock  and  strap,  and  fitted  inside .  .  $4. 50  to  $6 

MISCELLANEOUS 

Plain  tripod  legs  only,  for  Engineers'  Transit  or  Level,  per  set  $5.00 
Split  tripod  legs  only,  for  Engineers'  Transit  or  Level,  per  set  7.00 
Extension  tripod  legs  only,  for  Engineers'  Transit  or  Level, 

per  set 10.00 

Clamp  screw  and  band  for  extension  leg,  each .85  $0.05 

Tripod  head  only,  with  bolts  and  nuts,  for  Engineers'  Tran- 
sit or  Level 5.00  .50 

Wooden  cap  with  brass  screw-plate,  to  fit  tripod  head 75  .12 

Brass  bolt  and  nut  to  fit  tripod  head,  each 50  .05 

Metal  point  or  shoe  for  tripod  leg,  each 50  .05 

Leather  ring  to  bind  tripod  legs  together 10  .02 

Leather  strap  and  buckle  for  Transit  or  Level  Box 50  .15 

Leather  strap  and  handle  for  carrying  extension  tripod 50  .10 

Steel  screw-driver  with  wooden  handle 25  .05 

Steel  adjusting-pins,  each 05  .01 

Rubber  tips,  for  bottom  of  instrument  box,  per  set 40  .08 

Reading-glass,  for  Transit 75  .02 

Brass  Plummet  with  screw  cap,  for  Transit  or  Level 1.50  .20 

Waterproof  hood,  for  Transit  or  Level 1.00  .06 

Chamois  skin,  large  size,  best  quality 65  .05 

Clamp  with  scale  and  clamp  screw,  for  New  York  rod 3.00  .15 

Clamp  with  scale  and  clamp  screw,  for  Philadelphia  rod. .  .  .      3.00  .15 
Target  with  clamp  screw  and  spring,  for  New  York  or  Phila- 
delphia rod 4.50  .35 

Chain  handle,  with  staple  and  nuts,  each 75  .08 

Chain  tallies,  per  set  of  9 50  .06 


266  W.  «5r»  L.  E.   GURLEY,    TROY,  N.    Y. 

SPECIAL   NOTICE 

A  Transit  with  plain  telescope  is  one  without  any  attach- 
ments or  extras,  such  as  the  clamp  and  tangent,  vertical  circle 
and  level. 

The  telescopes  of  our  Transits  Nos.  1  to  17,  25  to  90 
and  110  to  117  are  furnished  with  rack  and  pinion  move- 
ment to  both  eyepiece  and  objective,  without  extra  charge. 

In  Transits  Nos.  20,  100,  102  and  105  the  objective  is 
focused  by  a  rack  and  pinion  and  the  eyepiece  by  a  spiral 
movement. 

We  have  recently  introduced  an  important  modification  of 
the  telescopes  used  on  all  our  Transits,  so  that  they  can  be 
focused  on  an  object  as  near  as  four  and  one-half  feet  from 
the  center  of  the  instrument. 

Our  Transits  Nos.  1  to  105  are  furnished  with  shifting- 
center  to  the  leveling-head,  and  with  a  tripod  and  leveling- 
screws,  and  clamp  and -tangent  to  spindle.  Transits  Nos.  20, 
25  to  31,  100  and  102,  have  tripods  with  extension  legs.  For 
prices  of  plain,  split-leg  and  extension  tripods  see  pages 
280  and  281. 

The  limbs  of  our  Transits  Nos.  1  to  102  are  graduated  on 
sterling  silver.  The  graduation  is  usually  to  half-degrees,  and 
is  read  by  vernier  to  single  minutes.  A  finer  graduation  is 
furnished,  if  desired,  at  an  extra  cost.  See  pages  14  to  18 
and  page  275. 

The  vertical  circles  and  vertical  arcs  are  graduated  on 
sterling  silver.  The  circle  of  3*4  inches  diameter  is  gradu- 
ated to  degrees,  and  is  read  by  vernier  to  5  minutes.  The 
circles  of  4^  and  5  inches  diameter  and  the  arc  of  2^  inches 
radius  are  graduated  to  half-degrees,  and  are  read  by  vernier 
to  1  minute.  The  arc  of  3  inches  radius  is  graduated  to  20 
minutes  and  is  read  by  vernier  to  30  seconds. 


W.  6-  L.  E.   GURLEY,    TROY,  N.    Y.  267 

A  variation  arc  furnished  with  a  new  Engineers'  Transit, 
Nos.  1  to  16,  costs  extra  $4.00.  See  No.  130,  page  274. 

Our  Transits  Nos.  17  to  102  and  110  to  117  have  a  vari- 
ation arc  for  setting  off  the  magnetic  declination. 

A  leveling  tripod  head  with  plates,  leveling-screws  and 
clamp  and  tangent  movement,  fitted  to  Vernier  Transits,  costs 
extra  $13.00.  See  No.  176,  pages  132  and  275. 

Unless  otherwise  ordered,  platinum  stadia  wires  are 
always  furnished  with  every  Mountain  Transit,  with  all  Solar 
Transits,  and  with  the  Reconnoissance  Transits. 

Stadia  wires  are  furnished  without  extra  charge  if  requested 
when  ordering  any  new  Transit.  When  desired,  we  arrange 
the  stadia  wires  to  disappear,  or  be  out  of  focus,  when  the 
plain  cross-wires  only  are  in  use.  See  pages  9  and  262  to  264. 

A  dust  guard  to  the  objective  slide  is  furhised  without 
charge  with  new  Transits  Nos.  1  to  90  and  110  to  117  ;  but 
if  furnished  with  new  Transits  Nos.  100,  102,  or  105,  the 
extra  cost  is  $4.00.  See  pages  11,  162  and  275. 

Reflectors  to  the  limb  verniers  are  always  furnished  with 
Mountain  Transits  Nos.  25  to  31,  and  are  also  furnished  with- 
out charge,  if  requested,  with  new  Transits  Nos.  1  to  20  and 
35  to  90 ;  but  if  furnished  with  a  new  Transit  Nos.  100  to 
102,  the  extra  cost  is  $1.50. 

Each  Transit  is  packed  in  a  mahogany  case,  with  lock  and 
leather  strap,  and  has  a  plummet,  reading-glass,  adjusting- 
pins,  etc.  The  wood  box  for  the  Explorers'  Transit  is  leather 
covered.  The  box  for  the  Mountain  Transit  has  an  outside 
sole-leather  case  with  shoulder  straps. 


PRICE   LIST 

OF 

CIVIL  ENGINEERS' 

AND 

SURVEYORS'  INSTRUMENTS 

AND 

SUPPLIES 


PRICE   LIST 


FORTY-SECOND   EDITION 
TROY,   N.  Y.,   U.   S.   A.,   AUGUST,   1908 


ALL  PRICES  IN  THIS   WORK  ARH  IN  U.   S.   CURRENCY.     STATE  WHAT   EDITION  OF 
MANUAL  WHEN  ORDERING  GOODS,  AND  GIVE  CATALOGUE  NUMBER 


This  Price  List  supersedes  all  previous  Editions 

ENGINEERS'  TRANSITS 

No.  .  PRICE 

1  Engineers'  Transit,  two  verniers  to  limb,  4-inch  needle,  plain 

telescope $145.00 

2  Engineers'  Transit,  two  verniers  to  limb,  4-inch  needle,  with 

level  on  telescope  and  clamp  and  tangent  to  telescope  axis     163.00 

3  Engineers'  Transit,  two  verniers  to  limb,  4-inch  needle,  with 

4^-inch    vertical  circle,  level   on   telescope   and  clamp  and 
tangent  to  telescope  axis 175.00 

6  Engineers'    Transit,    two   verniers  to  limb,   4^-inch  needle, 

plain  telescope  .,., 150.00 

7  Engineers'   Transit,   two  verniers   to  limb,    4£-inch   needle, 

with  level  on  telescope  and  clamp  and  tangent  to  telescope 

axis 168.00 

8  Engineers'   Transit,   two   verniers   to   limb,   4£-inch   needle, 

with  4^-inch  vertical  circle,  level   on  telescope  and  clamp 

and  tangent  to  telescope  axis. 180.00 

9  Engineers'   Transit,   two   verniers   to   limb,   4^-inch   needle, 

with  vertical  arc  of  3  inches  radius  with  vernier  moved  by 
tangent  screw,  level  on  telescope  and  clamp  and  tangent  to 

telescope  axis 186.00 

10  Engineers'  Transit,  two  verniers  to  limb,  4J-inch  needle, 
with  vertical  arc  of  3  inches  radius  with  vernier  moved 
by  tangent  screw,  level  on  telescope  and  gradienter  com- 
bined with  clamp  and  tangent  to  telescope  axis 198.00 

12  Engineers'  Transit,  two  verniers  to  limb,  5-inch  needle,  plain 

telescope,  as  shown  on  page  G 150.00 

13  Engineers'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 

level  on  telescope  and  clamp  and  tangent   to  telescope  axis     168.00 

14  Engineers'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 

4^-inch  vertical  circle,  level  on  telescope  and  clamp  and 
tangent  to  telescope  axis 180.00 


W.  &  L.  E.   GURLEY,    TROY,  N.    K  271 

ENGINEERS'   TRANSITS 

No.  PRICE 

15  Engineers'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 

vertical  arc  of  3  inches  radius  with  vernier  moved  by  tan- 
gent screw,  level  on  telescope  and  clamp  and  tangent  to 
telescope  axis $186.00 

16  Engineers'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 

vertical  arc  of  3  inches  radius  with  vernier  moved  by  tan- 
gent screw,  level  on  telescope  and  gradienter  combined 
with  clamp  and  tangent,  as  shown  on  page  29.  .. 198.00 

17  Engineers'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 

variation  arc,  Solar  Attachment,  vertical  arc  of  3  inches 
radius  with  vernier  moved  by  tangent  screw,  level  on  tele- 
scope, and  clamp  and  tangent  to  telescope  axis,  as  shown 
on  page  3l" 250.00 

EXPLORERS'  TRANSIT 

20  Explorers'  Transit,  two  verniers  to  limb,  2f -inch  needle,  with 
variation  arc,  4-inch  vertical  circle,  level  on  telescope  and 
clamp  and  tangent  to  telescope  axis,  extension  tripod  with 
jointed  legs.  Instrument  is  packed  in  a  mahogany  case 
with  leather  cover  and  shoulder  strap.  See  page  33 $165.00 

LIGHT  MOUNTAIN  AND  MINING   TRANSITS 

25  Light  Mountain  Transit,  two  verniers  to  limb,  4-inch  needle, 

with  variation  arc,  telescope  of  finest  quality,  power  20 
diameters,  extension  tripod  shortening  to  half  length.  The 
instrument  is  packed  in  a  mahogany  case,  covered  with  a 
light  sole-leather  case,  with  straps  for  packing.  With  plain 
telescope $150.00 

26  Light  Mountain  Transit,   with  level  on  telescope  and  clamp 

and  tangent  to  telescope  axis 168.00 

27  Light  Mountain  Transit,  with  4^rinch  vertical  circle,  level  on 

telescope  and  clamp  and  tangent  to  telescope  axis 180.00 

28  Light  Mountain  Transit,  with  vertical  arc  of  2J  inches  radius 

with  vernier  moved  by  tangent  screw,  level  on  telescope 

and  clamp  and  tangent  to  telescope  axis .      186.00 

29  Light  Mountain  Transit,  with  vertical  arc  of  2£  inches  radius 

with  vernier  moved  by  tangent  screw,   level  on  telescope 

and  gradienter  combined  with  clamp  and  tangent 198.00 

30  Light  Mountain  Transit,,  with  Solar  Attachment,  vertical  arc 

of  2^  inches  radius  with  vernier  moved  by  tangent  screw, 
level  on  telescope  and  clamp  and  tangent  to  telescope  axis, 
as  shown  on  page  37 245.00 

31  Light  Mountain  Transit,  with  Solar  Attachment,  Jones  lati- 

tude arc  complete,  level  on  telescope  and  clamp  and  tan- 
gent to  telescope  axis.  See  page  91 300.00 


272  W.   &•  L.  E.    GURLEY,    TROY,  N.    K 

SURVEYORS'    TRANSITS 

No.  WITH   TWO   VERNIERS   TO   LIMB  PRICE 

36     Surveyors'  Transit,  two  verniers  to  limb,  4-inch  needle,  plain 

telescope $125.00 

36  Surveyors'  Transit,  two  verniers  to  limb,  4 -inch  needle,  with 

level  on  telescope  and  clamp  and  tangent  to  telescope  axis     143.00 

37  Surveyors'  Transit,  two  verniers  to  limb,  4-inch  needle,  with 

4^ -inch  vertical  circle,  level  on  telescope  and  clamp  and 
tangent  to  telescope  axis 155.00 

45  Surveyors'  Transit,  two  verniers  to  limb,  5-inch  needle,  plain 

telescope 1 30.00 

46  Surveyors'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 

level  on  telescope  and  clamp  and -tangent  to  telescope  axis     148.00 
'47     Surveyors'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 
4^-inch  vertical  circle,  level  on  telescope  and  clamp  and 

tangent  to  telescope  axis,  as  shown  on  page  40 160.00 

48  Surveyors'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 
4^-inch  vertical  circle,  level  on  telescope  and  gradienter 
combined  with  clamp  and  tangent  to  telescope  axis 172.00 

66  Surveyors'  Transit,  same  as  No.  45,  but  with  5|-inch  needle.  .      130.00 
56     Surveyors' Transit,  same  as  No.  46,  but  with  5|-inch  needle.  .      148.00 

67  Surveyors'  Transit,  same  as  No.  47,  but  with  5^-inch  needle.  .      160.00 

68  Surveyors' Transit,  same  as  No.  48,  but  with  5| -inch  needle. .      172.00 
60     Surveyors'  Transit,  two  verniers  to  limb,  5-inch  needle,  with 

Solar  Attachment,  vertical  arc  of  3  inches  radius  with  ver- 
nier moved  by  tangent  screw,  level  on  telescope  and  clamp 
and  tangent  to  telescope  axis,  as  shown  on  page  47. 226.00 


W.  &>  L.  E.   GURLEY,   TROY,  N.    Y.  273 

SURVEYORS'    TRANSITS 

WITH    ONE   VERNIER   TO    LIMB 

No.  PRICK 

66     Surveyors'  Transit,  one  vernier  to  limb,  4-inch  needle,  plain 

telescope $110.00 

66  Surveyors'  Transit,  one  vernier  to  limb,  4-inch  needle,  with 

level  on  telescope  and  clamp  and  tangent  to  telescope  axis     128.00 

67  Surveyors'  Transit,  one  vernier  to  limb,  4-inch  needle,  with 

4J-inch  vertical  circle,  level  on  telescope  and  clamp  and 

tangent  to  telescope  axis 140.00 

76     Surveyors'  Transit,  one  vernier  to  limb,  5-inch  needle,  plain 

telescope 115.00 

76  Surveyors'  Transit,  one  vernier  to  limb,  5-inch  needle,  with 

level  on  telescope  and  clamp  and  tangent  to  telescope  axis, 

as  shown  on  page  44 133.00 

77  Surveyors'   Transit,  one  venier  to  limb,  5-inch  needle,  with 

4^-inch  vertical  circle,  level  on  telescope  and  clamp  and 
tangent  to  telescope  axis 146.00 

78  Surveyors'  Transit,  one  vernier  to  limb,  5-inch  needle,  with 

4^-inch  vertical  circle,  level  on  telescope  and  gradienter 
combined  with  clamp  and  tangent  to  telescope  axis 157.00 

85  Surveyors'    Transit,    same    as    No.    75,    but    with   5^-inch 

needle 115.00 

86  Surveyors'     Transit,    same    as    No.    76,    but   with    5£-inch 

needle 133.00 

87  Surveyors'     Transit,    same    as    No.     77,    but   with    5^-inch 

needle 145.00 

88  Surveyors'    Transit,    same    as    No.     78,    but    with    5^-inch 

needle 157.00 

90     Surveyors'   Transit,  one  vernier  to  limb,  5-inch  needle,  with 

I  Solar  Attachment,  vertical  arc  of  3  inches  radius  with 
vernier  moved  by  tangent  screw,  level  on  telescope  and 
clamp  and  tangent  to  telescope  axis 211.00 


RECONNOISSANCE   TRANSIT 


Reconnoissance  Transit,  one  vernier  to  limb,  3^-inch  needle, 
with  3^-inch  vertical  circle,  level  on  telescope  and  clamp 
and  tangent  to  telescope  axis,  leveling-screws,  and  clamp 
and  tangent  to  spindle,  and  extension  tripod,  as  shown  on 
page  49 $115.00 

Reconnoissance  Transit,  same  as  No.  100,  but  with  4^-inch 
vertical  circle  with  vernier  reading  to  one  minute 122.00 


274  W.  &>  L.  E.   GURLEY,    TROY,  N.    Y. 

BUILDERS'  TRANSIT 

No.  PRICE 
105     Builders'  Transit,  with  level  on  telescope,  clamp  and  tangent 
to  telescope  axis  and  to  limb  and  spindle,  and  with  level- 
ing-screws  and  tripod,  as  shown  on  page  51 $80.00 

VERNIER   TRANSIT   COMPASSES 

110  Vernier   Transit,   5-inch   needle,   plain   telescope,   compass 

tripod $  70.00 

111  Vernier  Transit,  5-inch  needle,  with  level  on  telescope  and 

clamp  and  tangent  to  telescope  axis 88.00 

112  Vernier  Transit,  5-inch  needle,  with  3|-inch  vertical  circle, 

level  on  telescope  and  clamp  and  tangent  to  telescope  axis       96.00 

115  Vernier   Transit,    (>-inch   needle,   plain    telescope,  compass 

tripod 75.00 

116  Vernier  Transit,  6-inch  .needle,  with  level  on  telescope  and 

clamp  and  tangent  to  telescope  axis 93.00 

117  Vernier  Transit,  '6-inch  needle,  with  3^-inch  vertical  circle, 

level  on    telescope    and  clamp  and  tangent  to  telescope 

axis,  as  shown  on  page  53 101.00 

ATTACHMENTS  AND  EXTRAS  FOR  TRANSITS 

PRICE        POST,   j 

130  Variation  Arc  added  to  a   new  Engineers'    Transit, 

Nos.  1  to  16,  if  ordered  with  the  Transit $  4.00 

131  Variation  Arc  added  to  Transits  when  sent   for   re- 

pairs       15.00 

135  Vertical  Circle,  3J  inches  diameter,   with  vernier  to 

5  minutes,,  see  pages  55  to  57 8.00     $0.15 

136  Vertical  Circle,  4£  inches  diameter,  with  vernier  to  1 

minute,  see  page  55 12.00         .20 

137  Vertical  Circle,   5  inches  diameter,  with  vernier  to  1 

minute 15.00         .20 

138  Vertical  Circle,  5  inches  diameter,  with  two  opposite 

double  verniers  to  1  minute,  see  page  56 35.00         .35 

139  Vertical  Arc,  1\  inches  radius,  with  vernier  to  1  min- 

ute moved  by  tangent  screw,  see  page  58 18.00         .20 

140  Vertical    Arc,    3    inches  radius,    with  vernier  to  30 

seconds  moved  by  tangent  screw,  see  page  58 18.00         .20 

141  Aluminum  Guard  for  Vertical  Circle,  see  page  57  ...       6.00 
145     Level  on  Telescope  with  ground  vial  and  scale,  see 

page  59 12.00         .25 

148  Clamp  and  tangent  to  telescope  axis,  see  page  59  ...        6.00         .13 

149  Beaman    Stadia   Arc    attached   to   new   Transit,  see 

pages  62  and  63 15.00 

"150     Gradienter   combined  with   clamp  and  tangent,    see 

page  64 18.00         .25 


W.   6-  L.  E.   GURLEY,    TROY,  N.    Y.  275 

ATTACHMENTS   AND   EXTRAS   FOR   TRANSITS 

No.  PRICE        POST. 

151  Platinum  Stadia  wires,  adjustable,  and  diaphragm $5.00     $0.15 

152  Platinum  Stadia  wires,  fixed,  and  diaphragm 7.00         .16 

154  Dust  Guard  to  objective  slide,  see  page  11 6.00 

155  Rack  and  Pinion  movement  to  eyepiece 5.00 

167  Sights  on  Telescope  with  folding  joints,  see  page  61 ..     8.00 

168  Sights  on  Standards  at  right  angles  with  telescope, 

see  page  61 8.00 

160  Detachable    Side    Telescope    and    Counterpoise,    for 

vertical  sighting,  see  page  66 25.00         .60 

161  Detachable   Riding    Telescope,    for  vertical  sighting, 

see  page  66 25.00         .50 

165  Reflector  for  illuminating  cross- wires,  see  page  67.  ...     4.00         .16 

166  Reflector     for     illuminating      cross-wires     of     large 

Y  Level 5.00  .15 

168     Diagonal  Prism  for  eyepiece  of  telescope,  see'page  67  8.00  .16 

170     Plummet  Lamp  for  Mine  Engineering,  see  page  68.  ..  10.00  .36 

173  Quick-Leveling  Attachment 6.00  .35 

174  Quick-Leveling  Attachment,  if  ordered  with  any  new 

Transit  Nos.  1  to  105 5.00 

176  Leveling-Head  with  plates,  leveling-screws  and  clamp 

and  tangent,   fitted  to  Transits  Nos.    110  to    117, 

see  page  132 13.00 

180  Attached  Magnifier  with  three  universal  joints,  to 

read  verniers,  each 5.00 

185  Graduation  of  limb  to  read  to  20  or  30  seconds, 

extra .  10.00 

183  Graduation  of  limb  to  read  to  10  seconds,  extra 30.00 

187  Graduation  of  4£  or  5-inch  vertical  circle  to  read  to  20    - 

or  30  seconds,  extra 5.00 

188  Graduation  of  No.  138  Vertical  Circle  to  read  to  20 

or  30  seconds,  extra.  . ' 10.00 

190     Solar  Attachment  with  declination  arc,  hour  circle  and 

polar  axis,  see  page  69 60.00         .30 

192  Solar  Screen  to  fit  eyepiece  of  telescope,  see  page  89. .      5.00         .12 

193  Patent    Latitude    Level,    for   use    with   Solar  Transit, 

see  page  90 . '   6.00         .15 

195  Jones  Latitude  Arc,  with  reversible  level,  see  page  91  73.00 

196  Striding  or  Adjusting-Level,  see  page  95 3.00         .15 

For  Tripods,  see  pages  18fi  to  189,  and  280  and  281.     For  Leather 
Cases,  see  pages  190  and  282 

SOLAR   COMPASS  PRICB 

210     Burt  Solar  Compass,  with  leveling-screws  and  clamp  and 

tangent  to  spindle,  and  tripod,  see  page  107 $210.00 

For  Pocket  Solar  Compass,  see  No.  275,  and  pages  142  and  277. 


276  W.  &  L.  E.   GURLEY,    TROY,  N.    K 

RAILROAD   COMPASSES 

No.  PRICE 

215  Railroad  Compass,  two  verniers  to  limb,  limb  reading  to  1 

minute,   5-inch  needle,  brass  cover,  outkeeper,  and  staff 
mountings 170.00 

216  Railroad  Compass,  two  verniers  to  limb,  limb  reading  to  1 

minute,   5^ -inch  needle,  brass  cover,  outkeeper,  and  staff 

mountings,  see  page  114 75.00 

220  Railroad  Compass,  one  vernier  to  limb,  limb  reading  to  1 
minute,  5  £ -inch  needle,  brass  cover,  outkeeper,  and  staff 
mountings,  see  page  116 60.00 

These  Compasses  should  always  be  used  on  a  tripod  when  practicable. 
Tripods  Nos.  415,  420,  and  425  are  adapted  for  use  with  these  Compasses. 

VERNIER  COMPASSES 

225  Vernier  Compass,  4-inch   needle,    brass  cover,    outkeeper, 

and  staff  mountings $30.00 

226  Vernier  Compass,   5-inch  needle,    brass   cover,    outkeeper, 

and  staff  mountings 35.00 

227  Vernier  Compass,   6 -inch  needle,    brass   cover,    outkeeper, 

and  staff  mountings,  see  page  118 40.00 

PLAIN   COMPASSES 

230  Plain  Compass,  4-inch  needle,  brass  cover,  outkeeper,  and 

staff  mountings $25.00 

231  Plain  Compass,  5-inch  needle,  brass  cover,  outkeeper,  and 

staff  mountings 30.00 

232  Plain  Compass,  6-inch  needle,  brass  cover,  outkeeper,  and 

staff  mountings,  see  page  130 35.00 

Compasses  Nos.  210  to  232  are  packed  in  mahogany  case,  with  lock  and 
leather  strap.  A  Compass  Tripod  (our  No.  415)  will  be  furnished  with  any  of 
these  Compasses,  Nos.  215  to  232,  at  an  extra  cost  of  $5.00;  and  if  the  staff 
mountings  are  omitted  we  deduct  $2.00. 

ATTACHMENTS   AND   EXTRAS    FOR  COMPASSES 

PRICE  POST. 

240  Compound  Tangent  Ball-Spindle,  see  page  131 $  9.00  $0.30 

241  Leveling- Adopter,  large  size,  see  page  131 7.00  .40 

242  Leveling-Head  with  plates,  leveling-screws  and  clamp 

and  tangent,  fitted  to  use  with  tripods  Nos.  401, 

406,  411,  415,  420,  and  425,  see  page  132 13.00 

246     Compass  Tripod  Mountings,  without  the  legs 4.00         .60 

For  Tripods,  see  pages  186  to  189  and  281.     For  Leather  Cases, 
see  pages  190  and  282. 


W.   &  L.  E.    G'URLEY,    TROY,  N.    Y.  277 

TELESCOPIC   SIGHT.     Patented 

ATTACHABLE  TO   COMPASS   SIGHT.     SEE  PAGES  133  TO  139 

No.  PRICE        POST. 

261  Achromatic  Telescope,  9-inch,  power  about  20  diame- 

ters, see  page  133 $18.00     $0.45 

262  Achromatic  Telescope,  9-inch,  same  as  No.  261,  and 

with  stadia  wires 20.00         .50 

We  add  to  the  Telescopic  Sight  the  following  extras,  at 
prices  named  : 

265  Vertical  Circle,  with  vernier  to  5  minutes 5.00 

266  Level  on  Telescope,  with  ground  and  graduated  vial  5.00 

267  Clamp  and  Tangent  to  telescope  axis 5.00 

268  Offset  standard  with  counterpoise,  to  bring  the  tele- 

scope over  the  line  of  zeros 7.50         .50 

POCKET   SOLAR   COMPASS 

275  Pocket  Solar  Compass,  one  vernier  to  limb,  limb  read- 
ing to  1  minute,  3-inch  needle,  with  two  levels, 
folding  sights  and  staff  mountings,  see  page  142. .  .$100.00 

Pocket  Solar  Compass,  with  light  tripod 105.00 

Pocket  Solar  Compass,  with  light  extension  tripod.  .    110.00 
Pocket  Solar  Compass,   with  light  extension  tripod, 

and  leveling-head  with  clamp  and  tangent 120.00 

Side  Telescope  and  Counterpoise  fitted  to  new  Pocket 

Solar  Compass 25.00 

POCKET   RAILROAD   COMPASSES 

285  Pocket  Railroad  Compass,  one  vernier  to  limb,  limb 
5  inches  diameter  reading  to  one  minute,  and  with 
clamp  and  tangent,  3^-inch  needle,  folding  sights, 
two  levels  and  staff  mountings,  see  page  145 $40.00 

288  Pocket  Railroad  Compass,  one  vernier  to  limb  with 
clamp  and  tangent,  limb  inside  the  compass  circle 
and  reading  to  1  minute,  4^-inch  needle,  folding 
sights,  two  levels  and  staff  mountings 33.00 

291  Pocket  Railroad  Compass,  4i-inch  needle,  clamp  and 
tangent  to  limb,  limb  reading  to  1  minute,  clamp 
and  tangent  to  spindle,  and  fitted  with  our  Tele- 
scopic Sight  No.  261,  with  extras  of  level,  vertical 
circle  to  o  minutes,  and  clamp  and  tangent  to  tele- 
scope axis,  and  with  tripod .  .  , 76,00 


278  W  &  L.  E.   GURLEY,    TROY,  N,    Y. 

POCKET   RAILROAD   COMPASSES 

No.  PRICE        POST. 

292  Pocket  Railroad  Compass,  same  as  No.  291,  but  with 

Telescope  No.  262 $78.00 

293  Pocket  Railroad  Compass,    same  as   No.    292,    and 

with    Leveling-Adopter,    complete    as    shown    on 

page  147 83.00 

POCKET   VERNIER    COMPASSES 

300  Pocket  Vernier  Compass,  3£-inch  needle,  folding 

sights,  two  levels  and  staff  mountings,  see  page  149  $16.00  $0.70 

305  Pocket  Vernier  Compass,  4|-inch  needle,  folding 

sights,  two  levels  and  staff  mountings,  see  page  149  18.00  1.10 

311  Pocket  Vernier  Compass,  42-inch  needle,  clamp  and 

tangent  to  spindle,  and  fitted  with  our  Telescopic 
Sight  No.  261,  with  extras  of  level,  vertical  circle 
to  5  minutes,  and  clamp  and  tangent  to  telescope 
axis,  and  with  tripod 61.00 

312  Pocket  Vernier  Compass,  same  as  No.  311,  but  with 

Telescope  No.  262,  see  page  151 63.00 

POCKET    PLAIN    COMPASSES 

315  Pocket  Plain  Compass,  2|-inch  needle   and   folding 

sights $  8.00 

316  Pocket  Plain  Compass,  2£-inch  needle,  folding  sights 

and  staff  mountings,  see  page  152 10.00 

317  Pocket  Plain  Compass,   3^-irich  needle   and   folding 

sights 10.00 

318  Pocket  Plain  Compass,  3|-inch  needle,  folding  sights 

and  staff  mountings,  see  page  152 12.00 

319  Pocket  Plain  Compass,  3^-inch  needle,  folding  sights, 

two  levels  and  staff  mountings 13.50 

EXTRAS   FOR   POCKET   COMPASSES 

325  Clamp   and   Tangent  fitted  to  ball-spindle  of  Com- 

passes Nos.  285,  288,  300,  305,  and  315  to  319  ..  $  5.00 

326  Rack  and  Pinion  to  variation  arc  of  Compasses  Nos. 

288  to  312 4.00 

327  Leveling-Adopter,  small  size,  see  page  152 5.00 

328  Leveling-Head  with  plates,  leveling-screws  and  clamp 

and  tangent  to  spindle 10.00 

For  Tripods,  see  pages  186  to  189  and  281.     For  Leather  Cases, 
see  pages  19Q  and  282- 


IV.  6-  L.  E.   GURLEY,   TROY,  N.    Y.  279 

GEOLOGISTS'  AND  CLINOMETER   COMPASSES 

No.  PRICE       POST. 

335  Geologists'  Compass  (of  aluminum),  graduated  mov- 
able sighting-circle,  graduated  base,  variation  arc, 
folding  sights,  two  levels,  clinometer  and  staff 
mountings,  see  page  153 $24.00  $0.35 

338  Clinometer  Compass  (of  brass),  3£-inch  needle, 
folding  sights,  square  base,  two  levels,  clinometer 
and  staff  mountings,  see  page  154 16.00  .50 

A  small  light  tripod  for  these  compasses  costs  extra  $5.00. 


MINERS'   COMPASSES   OR  DIPPING-NEEDLES 

FOR   TRACING  VEINS   OF   MAGNETIC   IRON   ORE 

Miners'  Dip-Compass,  3-inch  needle  with  stop,  glass 

on  both  sides,  in  wood  case,  see  page  156 $16.00  $0.25 

Miners'  Dip-Compass,  3-inch  needle  with  stop,  glass 

on  both  sides,  with  brass  covers 16.00  .35 

Miners'  Dip-Compass,  3-inch  Norwegian  needle  with 
'stop,  glass  on  both  sides,  with  brass  covers,  see 
page  156 16.00  .36 

Miners'  Dip-Compass,  4-inch  Norwegian  needle  with 

stop,  glass  on  both  sides,  with  brass  covers 20.00  .50 


DIAL   COMPASSES 

348  Brass  Dial  Compass,  with  hour  circle  graduated  for 

any  latitude  as  ordered,  variation  arc,  graduated 
base,  one  folding  sight,  two  levels  and  clinometer, 
see  page  158 $18.00  $0.40 

349  Dial    Compass,    same   as    No.    348,    and   with   staff 

mountings  complete 20.50         .50 

350  Aluminum  Dial  Compass,  with  hour  circle  graduated 

for  any  latitude  as  ordered,  graduated  base,  gradu- 
ated movable  sighting-circle,  variation  arc,  one 
folding  sight,  one  removable  sight,  two  levels, 

clinometer  and  staff  mountings,  see  page  160 30.00         .45 

Extra  Hour  Circles,  graduated  for  any  latitude  as 
ordered,  to  fit  either  of  these  Dial  Compasses, 
each •.... 6.00  .12 

A  light  tripod   for    Dial  Compasses  Nos.   349  and  350  costs 
extra  $5.00. 


LEVELING-INSTRUMENTS 


ENGINEERS'  Y   LEVELS 

No.  PRICE 

375  Y   Level,   22-inch   telescope,  with  leveling-screws,  clamp 

and  tangent  and  tripod $115.00 

376  Y  Level,  20-inch  telescope,  with  leveling-screws,  clamp  and 

tangent  and  tripod,  see  page  163 110.00 

377  Y  Level,  18-inch  telescope,  with  leveling-screws,  clamp  and 

tangent  and  tripod 1 10.00 

378  Y  Level,  15-inch  telescope,  with  leveling-screws,  clamp  and 

tangent  and  tripod,  see  page  176 90.00 

ARCHITECTS'  Y    LEVELS 

380  Architects'   Level,   12-inch  telescope,   with  leveling-screws 

and  tripod,  see  page  177 $50.00 

381  Architects'  Level,  12-inch  telescope,   with  leveling-screws, 

clamp  and  tangent  and  tripod,  see  page  178 65.00 

A  compass,  without  sights  and  with  3-inch  needle,  can  be  attached  to  the 
telescopes  of  these  leveling-instruments,  Nos.  375  to  381,  and  used  to  obtain  the 
bearing  of  lines  when  desired  ;  its  extra  cost  is  $10.00.  Stadia  wires  are 
furnished  with  any  of  our  Y  Levels,  free  of  charge,  if  requested  when  the 
instrument  is  ordered. 

DRAINAGE   LEVELS 

385  Drainage  Level,  with  staff  mountings $15.00 

386  Drainage  Level,  with  staff  mountings  and  tripod 20.00 

387  Drainage  Level,  with -staff  mountings,  leveling-screws  and 

tripod,  see  page  182 25.00 

388  Drainage    Level,    same   as   No.    387,    and   with    compass 

attached,  see  page  183 30.00 

All  our  Levels,  Nos.  375  to  388,  are  packed  in  mahogany  case  with  lock, 
and  strap  or  handle.  For  Level  Tripods,  see  pages  186  to  189,  and  281.  For 
Leather  Cases,  see  pages  190  and  282. 

TRANSIT   TRIPODS 

400  Plain  Tripod  for  Transits  Nos.  1  to  90,  see  page  187 $10.00 

401  Plain  Tripod  for  Transits  Nos.  100  to  117 %  5.00 

406  Split-Leg  Tripod  for  Transits  Nos.  1  to  90,  see  page  188.  .  12.00 

406  Split-Leg  Tripod  for  Transits  Nos.  100  to  1 17 10.00 

410  Extension  Tripod  for  Transits  Nos.  1  to  90,  see  page  189.  .        15.00 

411  Extension  Tripod  for  Transits  Nos.  100  to  117 12.00 

280 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y. 


281 


No. 
415 
416 
420 
421 
425 
426 


COMPASS  TRIPODS 

Plain  Tripod  for  Compasses  Nos.  210  to  232,  see  page  187. 

Plain  Tripod  for  Pocket  Compasses  Nos.  275  to  319 

Split-Leg  Tripod  for  Compasses  Nos.  210  to  232 

Split-Leg  Tripod  for  Pocket  Compasses  Nos.  275  to  319. . . 

Extension  Tripod  for  Compasses  Nos.  210  to' 232 

Extension  Tripod  for  Pocket  Compasses  Nos.  275  to  319. .. 

LEVEL  TRIPODS 


430  Plain  Tripod  for  Levels  Nos.  375  to  378,  see  page  187 

431  Plain  Tripod  for  Levels  Nos.  380  to  388 

435  Split-Leg  Tripod  for  Levels  Nos.  375  to  378,  see  page  188. 

436  Split- Leg  Tripod  for  Levels  Nos.  380  to  388 

440  Extension  Tripod  for  Levels  Nos.  375  to  378,  see  page  189. 

441  Extension  Tripod  for  Levels  Nos.  380  and  381 

442  Extension  Tripod  for  Levels  Nos.  385  to  388 

When  ordering  a  separate  tripod,  the  customer  should  always 

specify  for  what  instrument  it  is  wanted. 

BRASS    PLUMMETS.      Plain 


PRICE 
$  5.00 

5.00 
10.00 

8.00 
12.00 
10.00 


$10.00 
5.00 
12.00 
10.00 
15.00 
12.00 
10.00 


No. 
450 


465 


PRICE  POST. 
Plummet,  screw  head,  steel 

point,  6  oz $1.00  $0.16 

452  Plummet,  screw  head,  steel 

point,  10  oz 1.60  .20 

Plummet,  screw  head,  steel 

point,  16  oz 2.00  .25 

Plummet,  screw  head,  steel 

point,  24  oz 2.75  .36 

Plummet,  screw  head,  steel 

point,  32  oz 3.50  .45 

Plummet,  screw  head,  steel 

point,  long  neck,  12  oz. . . .       2.00         .25 

BRASS   PLUMMETS.     Adjustable 

These  Plummets  have  a  concealed  reel,  R, 
around  which  the  string  is  wound  by  turning  the 
milled  head,  K,  on  top.  The  friction  upon  the  reel 
will  hold  the  Plummet  at  any  desired  point  of  the 
line. 

465     Adjustable  Plummet,  10  oz. ..     $2.50     $0.20 
469     Adjustable  Plummet,  30  oz. .  .       5.00         .45 


282  W.  &  L.  E.   CURLEY,   TROY,  N.    Y. 

No.                                                                                                                  PRICE  POST. 

472  Stake  Tacks,  galvanized,  2  oz.  box $0.15  $0.04 

473  Stake  Tacks,  galvanized,  1  Ib.  box 60  .20 

474  Plummet  Cord,  braided  linen,  per  25  yards 38  .04 

SOLE-LEATHER   CASES 

TO    FIT   OUTSIDE   THE    WOOD    BOX 

PRICE 

475  Leather  Case  and  Strap,  for  Engineers'  or  Surveyors' 

Transits,  price  according  to  size $8.00  to  $10. 00 

476  Leather  Case  and  Strap,   for  Mountain,  Reconnois- 

sance  or  Builders'  Transits 8.00 

477  Leather  Case  and  Strap,  for  Large  Solar  Compasses  10.00 

478  Leather  Case  and  Strap,  for  Surveyors'  Compasses, 

Nos.  215  to  232,  price  according  to  size 6.00  to     9.00 

479  Leather  Case  and   Strap,  for  Engineers'  Y  Levels, 

price  according  to  size 8.00  to    10.00 

480  Leather  Case  and  Strap,  for  Architects'  Levels 6.00 

481  Leather  Case  and  Strap,  for  Drainage  Levels 4.00 

LEATHER  CASE  AND  SHOULDER  STRAP  FOR  POCKET 
COMPASSES,  to  fit  outside  the  wooden  box,  see  page  190, 
sizes  as  follows  : 

PRICE        POST. 

485  Size  for  Compasses  Nos.  315,  316,  335,  340  to  344, 

348  to  350 : $2.50  $0.20 

486  Size  for  Compasses  Nos.  300,  317  to  319,  338,  345,  3.00  .30 

487  Size  for  Compasses  Nos.  275,  285,  288,  305 4.00  .50 

488  Size  for  Compasses  Nos.  291  to  293,  311,  312 6.00 

LEATHER  POUCH  AND  SHOULDER  STRAP,  fitted  to 
receive  Pocket  Compasses  without  the  wooden  box,  see 
page  190,  sizes  as  follows  : 

490  Size  for  Compasses  Nos.  315,  316,  335,  340  to  344, 

348  to  350 $2.00      $0.15 

491  Size  for  Compasses  Nos.  300,  317  to  319,  338,  345.      2.50          .25 

492  Size  for  Compasses  Nos.  288,  305 3.00          .35 

TRIPOD   CASES 

494  Leather  Case,  with  cap  and  carrying  handle,  for 

extension  tripod $10.00 

497  Canvass  Case,  with  leather  trimmings,  for  extension 

tripod 7.50 

We  are  prepared  to  make  to  order  Leather  Cases  and  Pouches  of 
any  style  and  size  that  may  be  desired.  See  page  190. 


ll\  &>  L.  E.    GURLEYy    TROY,  N.    Y.  283 

LEVELING-RODS.     SEE  PAGES  191  TO  203 

No.  .  PRICE 

500  Philadelphia  Rod,   2  ply,    7T3o    feet  closed,   sliding  to  13 

feet,   graduated  to  feet,   lOths  and  lOOths,  with  vernier 

reading  to  lOOOths $14.00 

500B  Philadelphia  Rod,  2  ply,  7T37  feet  closed,  sliding  to  13  feet, 
graduated  to  feet  and  lOths,  with  both  target  and  rod 
reading  by  natural  scales  to  half-hundredths 14.00 

501  Philadelphia   Rod,    3   ply,   5T3^  feet  closed,  sliding  to  13 

feet,  graduated  to  feet,  lOths  and  lOOths,  with  vernier 
reading  to  lOOOths 18.00 

501 B  Special  Self-reading  Rod,  3  ply,  7T6^  feet  closed,  sliding  to 
20  feet,  graduated  on  four  faces  to  feet  and  lOths,  and  on 
back  of  the  front  section  to  feet,  lOths  and  lOOths;  also 
reading  by  two  scales  to  half-hundredths.  With  alumi- 
num target  and  canvas  case * 20. 00 

502 A  Philadelphia  Mining  Rod,  2  ply,  3^  feet  closed,  sliding  to 
5  feet,  graduated  to  feet,  lOths  and  lOOths,  with  vernier 
reading  to  lOOOths -. .  .  12.00 

503  Boston  Rod,  2  ply,  6  feet  closed,  sliding  to  11   feet,  gradu- 

ated to  feet,  lOths  and  lOOths,  with  vernier  reading  to 
lOOOths. 14.00 

504  Troy  Rod,  2  ply,  6£  feet  closed,  sliding  to  12  feet,  gradu- 

ated to  feet,  lOths  and  lOOths,  with  vernier  reading  to 
lOOOths 10.00 

605  New  York  Rod,  2  ply,  6T%  feet  closed,  sliding  to  12  feet, 
graduated  to  feet,  lOths  and  lOOths,  with  vernier  reading 
to  lOOOths 14.00 

507  .  New  York  Rod,  3  ply,  5  feet  closed,  sliding  to  12£  feet, 
graduated  to  feet,  lOths  and  lOOths,  with  vernier  reading 
to  lOOOths 18.00 

509  New  York  Mining  Rod,  2  ply,  3T%  feet  closed,  sliding  to 

5T%  feet,  graduated  to  feet,  lOths  and  lOOths,  with  vernier 
reading  to  lOOOths 12.00 

510  Architects'    Rod,  2  ply,  5}  feet  closed,  sliding  to  10  feet, 

graduated  to  feet,  inches  and  16ths 6.00 

611  Architects'  Rod,  2  ply,  5£  feet  closed,  sliding  to  10  feet, 

graduated  to  feet,  lOths  and  lOOths,  with  vernier  reading 

to  lOOOths ; 6.00 

612  Machinists'  Rod,  one  piece,  6£  feet  long,  for  leveling  shaft- 

ing, graduated  to  feet,  inches  and  16ths 5.00 

513  Telemeter  or  Stadia  Rod,  without  target,  hinge  joint,  6  feet 

folded,  unfolding  to  12  feet,  graduated  to  feet,  lOths  and 

lOOths 12.00 

514  Telemeter  or  Stadia  Rod,  without  target,  hinge  joint,  7  feet 

folded,  unfolding  to  14  feet,  graduated  to  feet,  lOths  and 

lOOths 13.00 


284 


&  L.  E.  GURLEY,  TROY,  N.   K 


LEVELING -RODS 

No.  PRICE 

515  Telescopic  Rod,  3  ply,  without  target,  5  feet  closed,  sliding 

to  14  feet,  graduated  to  feet,  lOths  and  lOOths $22.00 

516  Cross  Section  Rod,  one  piece,  without  target,  10  feet  long,. 

with  level  vial  at  each  end,  graduated  to  feet,  lOths  and 

lOOths 10.00 

51 8A  Plain  Rod,  one  piece,  without  target,  10  feet  long,  gradu- 
ated to  feet,  lOths  and  lOOths 6.00 

518B  Plain  Rod,  without  target,  with  hinge  joint,  5  feet  folded, 

unfolding  to  10  feet,  graduated  to  feet,  lOths  and  lOOths,  8.00 

51 9A  Plain  Rod,  one  piece,  without  target,  12  feet  long,  grad- 
uated to  feet,  lOths  and  lOOths 7.00 

51 9B  Plain  Rod,  without  target,  with  hinge  joint,  6  feet  folded, 

unfolding  to  12  feet,  graduated  to  feet,  lOths  and  lOOths.  9.00 

520 A  Plain  Rod,  one  piece,  without  target,  14  feet  long,  grad- 
uated to  feet,  lOths  and  lOOths 8.00 

520B  Plain  Rod,  without  target,  with  hinge  joint,  7  feet  folded, 

unfolding  to  14  feet,  graduated  to  feet,  lOths  and  lOOths.  10.00 

521 B  Plain  Rod,  without  target,  with  hinge  joint,  8  feet  folded, 

unfolding  to  16  feet,  graduated  to  feet,  lOths  and  lOOths.  11.00 

522A  Plain  Rod,  2  ply,  without  target,  5^  feet  long,  sliding  to 

10  feet,  graduated  to  feet,  lOths  and  lOOths 8.00 

522B  Plain  Rod,  2  ply,  without  target,  6^  feet  long,  sliding  to 

12  feet,  graduated  to  feet,  lOths  and  lOOths 9.00 

522C  Plain  Rod,  2  ply,  without  target,  7T3^  feet  long,  sliding  to 

14  feet,  graduated  to  feet,  lOths  and  lOOths 10.00 

524A  Plain  Rod,  4  ply,  without  target,  3T3^  feet  long,  sliding  to 

lly^  feet,  graduated  to  feet,  lOths  and  lOOths 10.00 

Any  of  our  Leveling-Rods  made  with  metric  graduations  without  extra 
charge. 

Canvas  Case  for  regular  pattern  Philadelphia  or  New  York  Rod,  $3.00  ; 
other  sizes  and  styles  made  to  order. 


FLEXIBLE   OR   POCKET   LEVELING-RODS 


Made  of  canvas,   can  be  coiled  up  and  carried  in  pocket, 
fastened  to  a  board  with  thumb  tacks. 


In  use  it  is 


\    •  Os  *  hs.  *  LD  »  OO  * 

P:rl!lTlTlT|lT|lTlT|lTlT|)Tll 


.  W.  &  L.  E.   GURLRY,    TROY,  N.    K  285 

No  PRICE  POST. 
525A  Pocket  Rod,  8  feet  long,  graduated  to  feet,  lOths  and 

lOOths : $3.00  $0.22 

525 B  Pocket  Rod,  10  feet  long,  graduated  to  feet,  lOths  and 

lOOths 3.25  .25 

526  A   Pocket  Rod,  12  feet  long,  graduated  to  feet,  lOths  and 

lOOths 4.00  .28 

526 B    Pocket   Rod,   12   feet   long,  graduated  to  feet,  inches 

and  8ths 4.00  .28 

527  Pocket   Rod,  14   feet    long,  graduated  to  feet,  lOths 

and  lOOths 4.50  .30 

528'     Pocket  Rod,  3^  meters  long,  graduated  to  centimeters      4.00  .30 

COMBINED   LEVELING-POLE   AND   FLAGSTAFF 

PRICK 

530  Wood  Leveling- Pole  and  Staff,  7  feet  long,  see  page  202. .  .  $5.00 

531  Wood  Leveling- Pole  and  Staff,  9  feet  long 6.00 


WOOD   AND   IRON   FLAGSTAFTS.     SEE  PAGE  203 

These  staffs  are  divided  in  feet,  which  are  painted  alternately 
red  and  white. 

534  Wood  Staff,  6  feet  long,  with  metal  shoe $2.00 

535  Wood  Staff,  8  feet  long,  with  metal  shoe 2.26 

536  Wood  Staff,  10  feet  long,  with  metal  shoe 2.50 


537A  TO  538B 

537 A  Wood  Staff,  round,  6  feet  long,  with  one  screw-joint 4.50 

53  7  B  Wood  Staff,  round,  6  feet  long,  with  one  screw -joint  and 

with  canvas  case 7.00 

538 A  Wood  Staff,  rouncV,  9  feet  long,  with  two  screw-joints 7.60 

538B  Wood  Staff,  round,  9  feet  long,  with  two  screw-joints  and 

with  canvas  case 10.50 


286  W.  &>  L.  E.    GURLEY,    TROY,  N.    Y. 

No.  pRICE 

539       Aligning  or  Ranging-Pole,  6  feet  long,  hung  in  gimbals.  .  .      $4.00 

The  aligning-pole  consists  of  an  iron  tube,  \\  of  an  inch  diameter,  6  feet 
long,  and  being  hung  in  gimbals  always  assumes  a  vertical  position. 

541        Iron  Tubular  Ranging-Pole,  6  feet  long,  ||  inch  diameter.         2.75 

543  Iron  Tubular  Ranging-Pole,  8  feet  long,  \\  inch  diameter.        3.00 

544  Iron  Tubular  Ranging-Pole,  10  feet  long,  ||  inch  diameter.        3.50 

Any  of  the  above  staffs  and  poles  with  metric  graduations  ( five  to  a  meter.) 
at  same  price. 

PRICE     POST. 

545  Rod  Level,  for  plumbing  a  Rod  or  Staff,  see  page 

204 $3.00    $0. 15 

546  Circular  Rod  Level,  with  folding  joint,  see  page  204       3.00         .15 


W.  &>  L.  E.   GURLEY,    TROY,  N.    Y.  287 

PLANE-TABLE    OUTFITS 

PRICE 

Plane-Table,  with  board  30  x  24  inches,  mounted  on  large 
tripod  with  leveling-socket  and  clamp,  and  with  plumb- 
ing-arm, plummet  and  clamps  for  paper $45.00 

Set  of  three  leveling-screws,  No.  563 10.00 

Clamp  and  tangent,  for  orienting,   No.  564 10.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  telescope  11  inches  long,  with  stadia,  4^-inch 
vertical  circle  to  1  minute,  level  on  telescope  and  clamp 
and  tangent,  on  column,  power  of  telescope  24  diameters, 
see  page  213,  No.  583 90.00 

Total,  as  shown  on  page  208 $170.00 

Plane-Table,  with  board,  tripod,  etc.,  as  in  No.  549 $45.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  telescope  11  inches  long,  with  stadia,  4^-inch 
vertical  circle  to  1  minute,  level  on  telescope  and  clamp 
and  tangent,  on  column,  power  of  telescope  24  diameters, 
see  page  213,  No.  583 90.00 

Total $150.00 

Plane-Table,  with  board,  tripod,  etc.,  as  in  No.  549 $45.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  telescope  9  inches  long,  power  20  diameters, 
with  stadia,  vertical  circle  to  1  minute,  level  on  telescope 
and  clamp  and  tangent,  on  column,  see  pages  205  and 
213,  No.  582 70.00 

Total,  as  shown  on  page  205 $130.00 

Plane-Table,  with  board,  tripod,  etc.,  as  in  No.  549 $45.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  telescopic  sight  No.  262,  with  stadia,  vertical 
circle  to  5  minutes,  level  and  clamp  and  tangent,  see  page 
212,  No.  581 50.00 

Total    $110.00 

Plane-Table,  with  board,  tripod,  etc.,  as  in  No.  549 $45.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  sight  vanes,  see  page  212,  No.  580 15.00 

Total $75.00 

560  Plane-Table,  with  board,  tripod,  etc.,  as  in  No.  549,  and 

omitting  Compass  and  Alidade $45.00 

663  Set  of  three  leveling-screws  for  Plane-Tables  Nos.  550  to 

560,  extra 10.00 

564  Clamp  and  tangent,  for  orienting,  for  Plane-Tables  Nos.  550 

to  560,  extra 10.00 


288  m  &  L.  E.    GURLEY,    TROY,  N.    K 

JOHNSON   IMPROVED   PLANE-TABLE 
AND   EXTRAS 

Prices  for  separate  parts.     See  engraving,  page  211. 
No.  PRICE 

570     Johnson. Plane-Table  Movement  and  plain  tripod $35.00 

If  tripod  has  extension  legs,  the  extra  cost  is  $10. 00. 

573  Drawing  Board,  31  x  24  inches,  with  brass  screw-plate  fitted, 

and  with  eight  clamp  screws  and  sockets  for  paper 5.00 

Canvas-covered  wooden  case  for  No.  573 6.00 

Flexible  canvas  case  for  No.  573 2.00 

574  Plumbing-arm  and  plummet 4.00 

575  Combined  Compass  with  levels  and  square  base 15.00 

JOHNSON    PLANE-TABLE   OUTFITS 

576  Johnson  Plane-Table  Movement  and  tripod,  with  drawing- 

board,  31  x  24  inches,  with  brass  screw-plate  fitted,  and 

with  eight  clamp  screws  and  sockets  for  paper $40.00 

Plumbing-arm  and  plummet 4.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  telescope  11  inches  long,  with  stadia,  4^,-inch 
vertical  circle  to  1  minute,  level  on  telescope  and  clamp 
and  tangent,  on  column,  power  of  telescope  24  diameters, 
see  page  213,  No.  583 00.00 

Total,  as  shown  on  page  211 $149.00 

577  Plane-Table,  with  tripod,  board,  etc.,  as  in  No.  576 $40.00 

Plumbing-arm  and  plummet 4.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  telescope  9  inches  long,  power  20  diameters, 

with  stadia,  vertical  circle  to  1  minute,  level  on  telescope 

and  clamp  and  tangent,  on  column,  No.'  582 70.00 

Total '$129.00 

578  Plane-Table,  with  tripod,  board,  etc.,  as  in  No.  576 $40.00 

Plumbing-arm  and  plummet 4.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  telescopic  sight  No.  262,  with  stadia,  vertical 

circle  to  5  minutes,   level   and  clamp  and  tangent,  see 

page  212,  No.  581 50.00 

Total $109.00 

579  Plane-Table,  with  tripod,  board,  etc.,  as  in  No.  576 $40.00 

Plumbing-arm  and  plummet! v 4.00 

Combined  Compass  with  levels  and  square  base 15.00 

Alidade  with  sight  vanes,  see  page  212,  No.  580 15.00 

Total..  .....  $74.00 


W.  <5r»  Z.  E.    GURLEY,    TROY,  N.    Y.  289 

ALIDADES 

No.  PRICH 

580  Alidade  with  Compass  sights,  see  page  212 $15.00 

581  Alidade  with  telescopic  sight  No.  262,  with  stadia,  vertical 

circle  to  5  minutes,  level  and  clamp   and   tangent,    see 

page  212 50.00 

682  Alidade  with  telescope  9  inches  long,  power  20  diameters, 

with  stadia,  vertical  circle  to  1  minute,  level  on  telescope 
and  clamp  and  tangent,  on  column,  as  in  engraving,  see 
pages  205  and  213 70.00 

683  Alidade  with  telescope  11  inches  long,  with  stadia,  4|-inch 

vertical  circle  to  1  minute,  level  on  telescope  and  clamp 
and  tangent,  on  column,  power  of  telescope  24  diameters, 
see  page  213 90.00 

684 A  Alidade  with  telescope  11  inches  long,  with  inverting  eye- 
piece, stadia,  vertical  arc  to  1  minute,  detachable  striding- 
level,  axis  tangent,  diagonal  prism  for  eyepiece.  The 
telescope  has  a  power  of  24  diameters,  and  is  mounted 
on  column,  see  page  214 118.00 

584B  Alidade  same  as  No.  584A,  but  with  erecting  eyepiece 118.00 

The  Alidades  as  above  described  can  be  used  with  any  of  our   Plane- 
Tables  Nos.  549  to  579,  and  will  be  sold  separately  at  the  prices  named. 


TRAVERSE    PLANE-TABLE  — U.   S.   G.   S.   PATTERN 

586  Improved    Traverse    Plane-Table  Board,    15x15    inches, 

with  Box  Compass  let  into  one  edge,  Ruler  Alidade  with 
graduated  edge,  folding  sights  and  leather  pouch,  tripod 
of  new  pattern  with  plunger  clamp  and  spring  board 
plate,  complete  as  shown  on  page  215 $80.00 

If  the  tripod  has  extension  legs,  add  extra  $5.00. 

When  desired,  we  furnish  separate  parts  of  this  Plane-Table 
at  the  following  prices  : 

587  Drawing-Board   with  improved  spring  board  plate,  tripod 

head  and  plain  legs :        12.00 

588  Box  Compass,  rectangular  metal  case,  4-inch  needle •  •  8.00 

589  Ruler  Alidade,  10  inches  long,  with  graduated  edge,  folding 

sights  and  with  leather  pouch 12.00 

590A  Pocket  Alidade,  6  inches  long,  with  graduated  edge  and 

folding  sights,  and  with  leather  case  with  pencil  pockets  7.50 

590B  Extra  folding  sights  fbr  Alidade  No.  590A,  per  pair 3.60 

691  Pocket  Alidade,  7  inches  long,  with  graduated  edge,  one 

peep  sight  and   one  folding  sight,  and  with  leather  case 

with  pencil  pockets 12.00 

Four  clamp  screws  and  sockets  for  board,  $0.75  extra. 


290  W.  <5r>  L.  E.    GURLEY,    TROY,  N.    K 

BATSON   SKETCHING-CASE 

No.  PRICE 
595     Batson  Sketching-Case,  as  shown  and  with  leather  case,  see 

pages  217  to  221   $30.00 

Wood    Staff,  about    2  feet    long,   with    steel-pointed   shoe, 

extra 1.00 

Plain  Tripod,  about  3£  feet  long,  extra 3.60 

CURRENT   METERS 

For  measuring  the  velocity  of  the  current  of  rivers  and  harbors, 
at  any  depth. 

600     Current  Meter  for  Harbors  and  Rivers,  see  page  224 $80.00 

604     Brass  Tubing,  graduated  to  feet  and  tenths,  and  jointed  in 

4-ft.  lengths,  per  length 5.00 

606     Lead  Weight,  60  Ibs.,  with  connections,  see  page  224 15.00 

609     Electric  Register,  see  pages  224  and  228 50.00 

612     Wet-Cell  Battery  of  three  cells,  in  box  with  lock  and  strap..  7.00 
614     Insulated  Copper  Wire  for  battery,  for  use  with  Meter  No. 

600,  per  foot 03 

616  Acoustic  Current  Meter  for  small  streams,  see  page  231. . .  .  50.00 

617  Electric   Current    Meter,  indicating  every  revolution,   with 

Vane  and  Torpedo  Weight,  for  small  streams,  complete 
with  electric  sounder  and  twenty  feet  of  cable,  see  page 

233 63.50 

Extra  length  of  cable,  per  foot  5  cents. 

618  Electric  Current  Meter,  with  base,  omitting  Vane  and  Lead 

Weight,  for  shallow  streams,  complete  with  four  feet  of 
graduated  brass  tube,  electric  sounder  and  twenty  feet  of 
cable,  see  page  237 63.50 

619-  Time- Recorder,  open  face,  nickel  case,  stem-winder,  with 
fly-back  attachment  for  starting  and  stopping.  Registering 
minutes,  seconds,  and  fifths  of  seconds 8.00 

621  Electric  Current  Meter,  indicating  every  fifth  revolution, 
with  Vane  and  Torpedo  Weight,  for  small  streams,  com- 
plete with  electric  sounder  and  twenty  feet  of  cable,  see 
page  238 63.50 

629     Boyden  Hook-Gauge,  see  page  239 25.00 

Water  Registers,  Tide  Gauges,  and  similar  instruments  made  to  order 
from  designs  submitted. 


W.  &  L.  E.    GURLEY,    TROY,  N.    K  291 

HAND    LEVELS 

PRICE  POST. 

640  Monocular  Hand  Level,  in  case,  see  page  241 $12.00  $0.20 

641  Binocular  Hand  Level,  in  case,  see  page  241 15.00  .35 

643     Locke    Hand    Level,     nickel-plated,    in    case,    see 

page  243 8.00         .20 

646     Abney  Level,  an  improved  Locke  Hand  Level,  giv- 
ing angles  of  elevation  ;    graduated  for  slopes,  as 

1  to  1,  2  to  1,  etc.,  in  case,  see  page  244 13.50         .25 

648     Abney  Level,  same  as  No.   646,  with  compass  and 

plain  staff  socket  attached 18.00         , 30 

Nos.  640  to  646  are  our  own  make ;   No.  648  is  of  foreign  make. 


292  W  &  L.  E.   GURLEY,    TROY,  N.    Y. 

CHAINS.     SEE  PAGES  245  TO  248 

No.  PRICE  POST. 

650  33  feet,    50  links,  oval  rings,  No.  10  refined  iron  wire  $2.25  $0.65 

651  33  feet,     50  links,  oval  rings,  No.     8  refined  iron  wire     2.50  .85 

652  66  feet,  100  links,  oval  rings,  No.  10  refined  iron  wire     3.50  1.15 

653  66  feet,  100  links,  oval  rings,  No.     8  refined  iron  wire     4.00  1.75 
656  33  feet,    50  links,  oval  rings,  No.  10  best  steel  wire. .     4.00  .65 
658  50  feet,     50  links,  oval  rings,  No.  10  best  steel  wire.  .     4.75  .80 
660  66  feet,  100  links,  oval  rings,  No.  10  best  steel  wire.  .     7.00  1.15 
662  100  feet,  100  links,  oval  rings,  No.  10  best  steel  wire.  .     8.50  1,50 

BRAZED   STEEL    CHAINS 

670  33  feet,  50  links,  No.  12  tempered  steel  wire,  brazed 

links  and  rings $  5.00     $0.45 

671  50  feet,  50  links,  No.  12  tempered  steel  wire,  brazed 

links  and  rings 6.00         .55 

672  66  feet,  100  links,  No.  12  tempered  steel  wire,  brazed 

links  and  rings 9.00         .70 

673  100  feet,   100  links,    No.   12   tempered   steel    wire, 

brazed  links  and  rings 10.00       1.00 

Our  brazed  steel  chains  displace  the  ordinary  chains 
wherever  they  are  tried,  on  account  of  superior  lightness 
and  strength.  They  are  practically  the  only  chains  now 
used  in  railroad  construction. 

Chains  of  two  and  four  poles  with  40  and  80  links, 
same  price  as  chains  of  50  and  100  links. 

Steel  snaps  to  make  full  chains  into  half-chains,  without 
extra  charge,  if  ordered  with  the  chain. 

GRUMMAN   PATENT   STEEL    CHAINS 

680  33  feet,  50  links,  No.  15  tempered  steel  wire,  weight 

1  Ib $  5.00    $0.28 

681  50   feet,    100   links,    No.    15   tempered   steel    wire, 

weight  1J  Ibs 6.00         .30 

682  66    feet,    100   links,    No.    15   tempered   steel    wire, 

weight  \\  Ibs 9.00         .35 

683  100   feet,    200  links,    No.    15  tempered  steel  wire, 

weight  1\  Ibs 11.00  .50 

685  50  feet,  100  links,  .No.  18  tempered  steel  wire, 

with  spring-balance,    level    and   thermometer,    for 

very  accurate  measurements,  weight  14^  oz 15.00  .30 

688  Spring-balance  for  10  Ibs.  strain  with  handle  and 

steel  snap,  to  use  with  chains  Nos.  680  to  683 2.50         .15 


W.  &•  L.  E.   GURLEY,  TROY,  N.    K  293 

VARA   CHAINS 

No.  PRICK       POST. 

690  10  varas,    50  links,  oval  rings,    No.    10  refined  iron 

wire $2.25     *0.55 

691  10  varas,   50    links,   oval    rings,   No.   8  refined  iron 

wire 2.50         .75 

694  20  varas,  100  links,  oval  rings,   No.    10  refined  iron 

wire 3.50       1.00 

695  20  varas,    100  links,    oval   rings,  No.    8  refined  iron 

wire 4.00  1.65 

700  10  varas,  50  links,  oval  rings,  No.  10  best  steel 

wire 4.00  .55 

704  20  varas,  100  links,  oval  rings,  No.  10  best  steel 

wire 7.00  1.00 

708  10  varas,  50  links,  oval  rings,  No.  12  tempered  steel 

wire,  brazed  links  and  rings 5.00  .35 

710  20  varas,  100  links,  oval  rings,  No.  12  tempered 

steel  wire,  brazed  links  and  rings 9.00         .65 

METER   CHAINS 

716  10  meters,  50  links,  oval  rings,  No.  10  refined  iron 

wire $2.25  $0.65 

716  10  meters,  50  links,  oval  rings,  No.  8  refined  iron 

wire 2.50  .85 

719  20  meters,  100  links,  oval  rings,  No.  10  refined  iron 

wire 3.50       1.15 

720  20  meters,    100  links,  oval   rings,  No.  8  refined  iron 

wire 4.00  1.75 

723  10  meters,  50  links,  oval  rings,  No.  10  best  steel 

wire 4.00  .65 

727  20  meters,  100  links,  oval  rings,  No.  10  best  steel 

wire 7.00  1.16 

730  10  meters,  50  links,  oval  rings,  No.  12  tempered  steel 

wire,  brazed  links  and  rings 5.00  .45 

732  20  meters,  100  links,  oval  rings,  No.  12  tempered 

steel  wire,  brazed  links  and  rings 9.00  70 

MARKING-PINS   AND   TIMBER-SCRIBE 

740  Set  of  11  Pins,  No.  4  iron  wire,  14  inches  long $1.25  $0.50 

742  Set  of  11  Pins,  No.  6  steel  wire,  14  inches  long 1.50  .40 

744  Set  of  11  Pins,  No.  6  steel  wire  weighted,  14  inches 

long 2.50  1.25 

746  Set  of  11  Pins,  No.  10  steel  wire,  9  inches  long,  in 

leather  pouch 2.00  .25 

748  Set  of  11  Pins,  No.  4  brass  wire,  14  inches  long 2.50  .50 

760  Timber- Scribe,  for  marking  trees,  posts  or  boards.  .  .  .  1.00  .15 


294 


&•  &  L.  E.   GURLEY,    TROY,  N.    Y. 
STEEL   RIBBON   CHAIN   TAPES 

\   INCH   WIDE,    AND  WITH   HANDLES   AND   REEL 


PRICE 

$3.50 

4.00 

4.50 

5.00 


No. 

760  Steel  Ribbon,  33  feet,  graduated  to  fifty  links  only  . 

761  Steel  Ribbon,  50  feet,  graduated  each  foot 

762  Steel  Ribbon,  66  feet,  graduated  to  100  links  only. . 

763  Steel  Ribbon,  100  feet,  graduated  each  foot 

764  Steel   Ribbon,  100  feet,  graduated  each  foot  (heavy 

ribbon) .  . .       6.00 

765  Steel  Ribbon,  200  feet,  graduated  each  foot  up  to  100 

feet,  and  the  last  100  feet  graduated  each  10  feet  .        7.50 

766  Steel  Ribbon,   200  feet,  graduated  each  foot  (heavy 

ribbon) 9.00 

767  Steel  Ribbon,  300  feet,  graduated  each  foot  up  to  100 

feet,  and  the  last  200  feet  graduated  each  10  feet.      10.00 

768  Steel  Ribbon,  300  feet,  graduated  each  foot  (heavy 

ribbon) 12.00 

The  50,  100,  200,  and  300  feet  Chain  Tapes  also  have  the  first  and  last  foot 

STEEL    RIBBON   BRIDGE   TAPES 

£    INCH   WIDE,    WITH    HANDLES   AND   EXTRA   FINE   REELS 


POST. 
$0.25 

.30 
.35 
.40 

.50 
.70 


lOths. 


No.  PRICE 

770  Steel  Ribbon,  300  feet,  graduated  each  5  feet $13.00 

771  Steel  Ribbon,  400  feet,  graduated  each  5  feet 15.00 

772  Steel  Ribbon,  500  feet,  graduated  each  5  feet. 17.00 

Our  Bridge  Tapes  are  mounted  on  substantial  wooden  reels  with 

aluminum  and  brass  mountings  and  swivel  handle. 

These  tapes  have  the  first  and  last  5  feet  graduated  each  foot. 

We  can  also  furnish  tapes,  Nos.  760  to  772,  graduated  each  meter  or  each 
vara.     See  page  251. 

Tapes,  Nos.  760  to  772,  have  etched  graduations. 


W.  &  L.   E.    GURLEY,   TROY,  N.    Y. 


295 


METALLIC    TAPES 

Made  of  linen  thread,  interwoven  with  fine  brass  wire.  They  are 
|  inch  wide,  and  in  leather  cases.  The  graduations  are  in  lOths  or  12ths 
of  a  foot,  as  desired,  on  one  side,  and  in  links  on  the  reverse  side. 


No.  PRICE  POST. 

780     Metallic  Tape,  33  feet,  in  lOths  or  12ths,  and  links. .  $2.10  $0.18 

782  Metallic  Tape,  50  feet,  in  lOths  or  12ths,  and  links. .  2.60  .20 

783  Metallic  Tape,  66  feet,  in  lOths  or  12ths,  and  links. .  3.00  .25 
786     Metallic  Tape,  100  feet,  in  lOths  or  12ths,  and  links  4.20  .30 

We  can  furnish  metallic  tapes  with  metric  or  vara  measure  on 
reverse  side,  instead  of  links,  at  an  extra  cost  of  one  cent  per  foot. 


METALLIC    TAPES   WITHOUT  .  CASES 


These  tapes  can  be  put  into  the  leather  cases  when  the  original 
tape  line  is  worn  out. 

790  Metallic  Tape,  33  feet,  in  lOths  or  12ths,  and  links, 

without  case  ................................     $1.10     $0.12 

791  Metallic  Tape,  50  feet,  in  lOths  or  12ths,  and  links, 

without  case  ................................        1.50         .15 

792  Metallic  Tape,  66  feet,  in  lOths  or  12ths,  and  links, 

without  case  ................................        1.80         .18 

794     Metallic  Tape,  100  feet,  in  lOths  or  12ths,  and  links, 

without  case  ................................       2.90         .20 


296  w-  &  L-  E-    GURLEY,    TROY,  N.    K 

STANDARD   AMERICAN   STEEL   TAPES 

|   INCH   WIDE,  IN   LEATHER    CASES;     THE  MOST   ACCURATE, 
DURABLE  AND   PORTABLE   MEASURES 


No.  PRICE  POST. 

800  Steel  Tape,  25  feet,  in  lOths  or  12ths,  and  links $  3.75  $0.15 

801  "      38  feet,                                                 4.30  .18 

802  «      50  feet,                                                 6.00  .20 

803  66  feet,  ....  7.60  .23 

804  75  feet,  ....  8.60  .25 

805  100  feet,                                                 10.60  .30 

806  150  feet,  ....  15.50  .45 

807  200  feet,                                               20.00  .60 


No. 
808 
809 
810 
811 
812 
813 


THE    "STAR"    STEEL    TAPE 

f    INCH    WIDE,  IN    NICKELED    BRASS   CASES 

Steel  Tape,  25  feet,  in  lOths  or  12ths,  and  links $3.00 

33  feet,                                                 ....  3.20 

50  feet,                                                 ....  3.60 

66  feet,                                                 4.40 

75  feet,                                                 4.80 

100  feet,                                                 6.40 

Steel  Tapes,  Nos.  800  to  879,  have  etched  graduations. 


$0.15 
.18 
.20 
.25 
.30 
.35 


W.  &  Z.  E.   GURLEY,   TROY,  N.    Y.  297 

CHESTERMAN'S    ENGLISH    STEEL   TAPES 

|    INCH    WIDE,   IN    LEATHER    CASES,    FOLDING    HANDLE 
No.  PRICE        POST. 

815  Steel  Tape,  33  feet,  in  lOths  or  12ths,  and  links.  . .  .     $5.20     $0.18 

816  "         "      50  feet,         "  "         ""....       7.20         .20 

817  "         "      66  feet,       "«  "         ««"....       9.20         .23 

819  "         "    100  feet,         "  ."         "      "     ....     12.80         .30 

AMERICAN   STEEL   TAPES.     PAINE' S  PATTERN 

\    INCH    WIDE,  IN    LEATHER    CASES,    FOLDING    HANDLES 
No. 

820  Steel  Tape,  33  feet,  in  lOths  or  12ths,  and  links.  . .  .     $4.40     $0.18 

821  »  "  50  feet,  "  "  "-."....  6.40  .23 

822  "  "  66  feet,  "  "  [."       "    ....  8.00  .28 

823  "  "  75  feet,  «  "  "       "    ....  9.60  .30 

824  "  "  100  feet,  "  "  "«....  12.00  .35 

AMERICAN  STEEL  TAPES.     PAINE' S  PATTERN 

\    INCH    WIDE,  IN    METAL   CASES,    FOLDING   HANDLES 
No. 

830  Steel  Tape,  25  feet,  in  lOths  or  12ths,  and  links.  .  .  .     $2.80    $0.15 

831  "  "  33  feet,  "  "  "       "    .'. . .  3.60  .18 

832  "  »  50  feet,  "  "  "«....  4.80  .23 

833  «  "  66  feet,  "  "  "«*....  6.40  .28 

834  "  "  75  feet,  "  «'  ""..'.,.  8.00  .30 

835  "  "  100  feet,  «'  «'  «'       ''..-.  9.60  .35 

Tapes,  Nos.  821  to  824,  and  832  to  835  (50  to  100  feet),  are  detach- 
able from  their  cases,  and  furnished  with  an  extra  handle,  No.  841, 
and  can  be  used  as  a  chain  tape. 

v 

EXTRAS   FOR  PAINE' S  STEEL   TAPES 

No. 

840  Compensating  Handles,   detachable,  with  graduated 

scale,  per  pair $2.40     $0.12 

841  Plain  Finger-ring  Handles,  detachable,  each .'40         .02 

843  Pocket  Thermometers,  each .85         .15 

844  Spring- Balance,  with  handle  and  snap 2.50         .15 

845  Spring- Balance  and  Level,  with  handle  and  snap  ...        4.00         .15 

Tapes,  Nos.  800  to  835,  are  graduated  to  feet,  lOths  and  lOOths  of 
a  foot,  or  to  feet,  inches  and  8ths  of  inches,  as  desired,  on  one  side,  and 
in  links  on  the  reverse  side. 

Tapes,  Nos.  820  to  835,  with  metric  or  vara  measure  on 
reverse  side  instead  of  links,  at  an  extra  cost  of  two  and 
one-half  cents  per  foot. 


298  W.  &>  L.  E.    GVRLEY,    TROY,  N.    Y. 

EXCELSIOR   STEEL   TAPES 

£   INCH   WIDE,  ON    BRASS    FRAME   WITH    HANDLE 


PRICE 

POST. 

33  feet, 

in  lOths  or  12ths,  and  links.  . 

.  $  5.00 

$0,20 

50  feet, 

a              a         «       tt 

.       6.40 

.25 

66  feet, 

«              a         tt       <( 

,  .       8.00 

.30 

100  feet, 

"              "         "       «    .  , 

,.     11.50 

.40 

150  feet, 

n              n         n      u 

.     17.00 

.60 

200  feet, 

It                             «                   U            11 

.     22.00 

50  feet, 

"              "         "  meters. 

7.65 

.25 

100  feet, 

«                                   «                       «C                  « 

.     14.00 

.40 

150  feet, 

«                                   ((                      <(                  14 

.     20.75 

.60 

200  feet, 

((                                   t(                      «                  4( 

.     27.00 

No. 

850  Steel  Tape, 

851 

852 

853   « .   « 

854A  « 

854B  " 

855   "    " 

858 

859A  " 

859B  " 

Tapes  Nos  850  to  854B  are  graduated  to  feet,  lOths  and  lOOths  of  a  foot,  or  to  feet, 
inches  and  8ths  of  inches,  as  desired,  on  one  side,  and  in  links  on  the  reverse  side. 

Tapes  Nos.  853  and  859B  have  metric  measure  on  the  reverse  side  instead  of  links. 

METRIC    AND   VARA   TAPES 

We  can  furnish  any  of  our  tapes,  Nos.  780  to  794  and  820  to  835,  with 
metric  or  vara  measure  only,  at  prices  for  regular  style  of  tapes  of  similar 
lengths  in  feet.  If  with  metric  or  vara  measure  on  reverse  side,  instead  of 
links,  the  extra  cost  will  be  as  stated  on  pages  294  and  296. 

NICKEL-PLATED   TAPES 

When  desired,  we  will  nickel-plate  our  steel  tapes,  Nos.  800  to  835  and 
850  to  859B,  to  protect  from  rust,  at  the  following  prices  : 

25        33        50        66        75       100       150     200     300     500  feet. 
Each,  $0.90     1,00     1,50     1.75     1.75     2,00     2,50  3,00    4,00   6.00 


L..E.   GURLEY,    TROY,  N.    Y. 


299 


POCKET    STEEL   TAPES 

IN  GERMAN  SILVER  CASES,  WITH  SPRING  AND  STOP 

No.  PRICE       POST. 

860     Pocket  Steel  Tape,  3  feet,  in  lOths  or  12ths $1.00     $0.11 

863         "         "         "      6  feet,         "             "     1.40         .12 

866         "         "         "    12  feet,         "             "     2.50         .15 

870     Pocket  Steel  Tape,    6   feet,   in   lOths  one  side  and 

12ths  reverse  side 1.60         .12 

873     Pocket  Steel  Tape,   12  feet,  in  lOths  one  side  and 

12ths  re  verse  side.... 2.80         .16 

875     Pocket  Steel  Tape,  3  feet,  in  lOths  or    12ths,    and 

meter 1.10         .11 

877     Pocket  Steel  Tape,  6  feet,  in  lOths  or  12ths,    and 

meter 1.60         .12 

879     Pocket  Steel  Tape,   12  feet,  in  lOths  or  12ths,  and 

meter..                                                      2.80         .16 


885 

PUNCH  AND  RIVETER,  FOR  REPAIRING  TAPE-LINES 

This  punch  cuts  a  clean  hole  in  steel  tapes  of  the  usual  thickness, 
and  the  eyelet  is  then  inserted  and  quickly  and  neatly  riveted.  The  Punch 
is  7f  inches  long. 

No.  PRICE        POST. 

885  Punch  and  Riveter,  with  eyelets $5.00     $0.30 

886  Extra   eyelets,    two   lengths,    two  packages  of  500 

each  length 1.25         .05 


SUPPLEMENT 

TO 

Forty-second  Edition  of  Manual 

August,  1908 


The  prices  in  this  Catalogue  may  vary  from   time  to  time,  on  account  of 
fluctuations  in  Market  Rates. 

This  Price   List  supersedes  all   previous   editions,  and   has   been   carefully 
revised  and  enlarged. 

When  ordering  goods  always  state  what  edition  of  Manual,  and  number 
in  Catalogue. 


DRAWING-INSTRUMENTS 

'T'O  GUIDE  the  surveyor  and  engineer  in  the  selection  of 
Drawing-Instruments,  we  here  add  a  detailed  description, 
with  illustrations  and  prices  of  the  separate  pieces  and  cases 
of  the  different  kinds  in  general  use. 

Those'  we  first  mention  are  of  Swiss  manufacture,  of  the 
finest  quality  and  finish,  and  are  made  of  the  best  German 
silver  and  English  steel. 

We  show  first  the  regular  patterns  and  then  those  with  the 
celebrated  pivot -joint. 

The  Alteneder  instruments  are  the  best  of  American 
manufacture,  and  are  equally  as  good  as  those  of  Swiss  make. 

The  fine  German  silver  instruments,  of  German  make,  are 
the  best  of  their  kind. 

300 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y.  301 

The  instruments  before  mentioned  are  intended  for 
engineers,  architects,  draftsmen,  machinists  and  students  in 
technical  schools. 

The  cheaper  German  silver,  brass  and  nickel -plated  in- 
struments are  for  common  school  use  and  elementary  practice. 

Parties  wanting  special  cases  made  up  can  select  the  pieces 
and  we  will  make  cases  to  suit,  at  an  additional  cost  of  from 
$2  to  $10,  according  to  the  size  and  quality  of  the  cases, 
which  are  made  of  morocco,  rosewood  or  mahogany. 

For  prices  of  regular  size  cases,  see  page  310. 

For  the  convenience  of  our  customers,  we  will  furnish  any 
articles  not  on  our  list,  but  described  in  the  catalogue  of  any 
American  manufacturer  or  dealer  in  mathematical  instruments, 
at  catalogue  prices. 


SPECIAL  NOTICE 

MANY  of  our  smaller  instruments,  such  as  drawing-instruments, 
pocket  compasses,  chains,  tapes,  smalt  packages  of  paper  and 
parts  of  large  instruments,  can  be  sent  by  mail  securely  packed,  and 
at  much  lower  rates  than  are  charged  by  express  companies.  Packages 
not  exceeding  four  pounds  in  weight  can  be  sent  in  this  way  within  the 
United  States,  Canada  and  Mexico  at  a  cost  of  one  cent  per  ounce. 

In  all  cases  where  goods  are  to  be  sent  by  mail,  the  cash  for  postage  as 
well  as  for  the  goods  must  accompany  the  order. 

The  postage  required  is  mentioned  in  the  second  column  of  the  Price  List, 
and  for  articles  worth  more  than  one  dollar  the  amount  named  for  postage 
includes  the  cost  of  registry. 

All  articles  can  be  registered  at  an  extra  cost  of  eight  cents  for  each 
package  besides  regular  postage.  Packages  for  registry  should  not  exceed 
four  feet  in  length. 

We  are  not  responsible  for  goods  lost  or  injured  when  sent  by  mail. 


W.  &  L.  E.    GURLEY,   TROY,  N,    Y. 


SUPERIOR   SWISS    DRAWING-INSTRUMENTS 

OF  GERMAN  SILVER,  EXTRA  FINE  FINISH 


1000 

No. 

1000 

1002 

1003 

1005 


1003 


1005 


1008 


1010 


101  1 

PRICE 

Plain  Dividers,  3^-inch,  with  handle $1.50 

Plain  Dividers,  4^-inch,  without  handle 1.50 

Plain  Dividers,  5-inch,  without  handle 1.75 

Hairspring  Dividers,  3^-inch,  with  handle 2.25 


POST. 

$0.10 

.12 

.12 

.10 


L.  E,    GURLEY,   TROY,  N. 


303 


No. 

1007 
1008 
1010 
1011 


Hairspring  Dividers,  4J-inch,  without  handle 

Hairspring  Dividers,  5-inch,  without  handle  ....... 

Pocket  Dividers,  5-inch,  with  sheath 

Three-legged  Dividers,  6-inch,  for  spacing  off  three 
points  . 


PRICK 

$2.25 

2.50 

2.50 

4.00 


1013     Whole  and  Half  Dividers,  7J-inch 3.50 


POST. 

$0.12 

.12 

.12 

.13 
.16 


1015    1016    1017      1019  1024 

1015  Compasses,  3£-inch,  with  two  fixed  needle  points.  .        3.00 

1016  Compasses,    3^-inch,    with    fixed   needle   and    pen 

points 3.00 


,10 

,10 


304 


W.  &  L.  E.   GURLEY,   TROY,  N.    K 


No.  PRICK        POST. 

1017  Compasses,  3£-inch,  with  fixed  needle  and  pencil 

points  ...  .................................     $3.00     $0.10 

1018  Compasses,  3^-inch,  with  fixed  needle  point,    and 

pen  and  pencil  points  ........................       4.50         .12 

1019  Compasses,   3^-inch,   with  pen,  pencil    and   needle 

points  ................  '.  ...................       5,00 

1020  Spring  Bow-Compasses,  3^  -inch,  with  long  handle, 

two  steel  points,  pencil  and  needle  points  and  two 

pen  points  for  ruling  parallel  lines  .............        7.00 

1022  Compasses,  5^-inch,  with  fixed  needle  point,  pen 

and  pencil  points  and  lengthening  bar.  .........       5.50 

1024  Compasses,  6-inch,  with  pen,  pencil  and  needle 

points  and  lengthening  bar  ...................       6.50 


12 


13 


15 


.15 


1028 


Drawn  out  for  small  circles 
1029 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y. 


305 


No. 
1026 


PRICK        POST 


Compasses,  6£-inch,  with  joint  in  each  leg,  pen, 
pencil,  and  needle  points,  dotting-pen  and 
lengthening  bar  ..............................  $9.00 

1028  Pocket-Compasses,  with  folding  points  .............     8.75 

1029  Pillar-Compasses,  with  handles,  pen,  pencil'  and  two 

needle  points  which  can  be  drawn  out  and  used  as 

a  small  bow-pen  and  bow-pencil  ................     9.75 


1033 
1034 
1035 
1039 
1040 

1041 
1042 

1046 
1047 

1048 
1049 


1033 


1034 


1035 


Steelspring  Bow-dividers,  with  ivory  handle,  3-inch,  1.50 

Steelspring  Bow-pen,  with  ivory  handle,  3-inch 2.00 

Steelspring  Bow-pencil,  with  ivory  handle,  3-inch..  2.00 
Steelspring  Bow-dividers,  with  ivory  handle,  3|-inch .  .  2.00 
Steelspring  Bow-dividers,  with  needle  point,  ivory 

handle,  3^-inch 2.50 

Steelspring  Bow-pen,  with  needle  point,  ivory 

handle,  3£- inch 2.50 

Steelspring  Bow-pencil,  with  needle  point,  ivory 

handle,  3^-inch 2.50 

Spring  Bow-pen, with  adjusting-screw 2.00 

Spring  Bow-pen,  with  adjusting-screw  and  pencil 

point 3.00 

Spring  Bow-pen,  with  adjustable  point,  for  small 

circles 3.00 

Spring  Bow-pen  and  pencil,  with  adjustable  point, 

for  small  circles ; 4.00 


$0.18 
.12 


.14 


.10 
.10 
.10 
.10 

.10 
.10 

.10 
.10 

.10 
.10 
.10 


W.  6-  L.   £.    GURLEY,    TROY,  N. 


1046 


1047  1048 

For  prices,  see  page  305. 


1049 


W.  &  L.  E.    GURLEY,    TROY,  N.    Y. 


307 


1055        1056       1057         1060  1062  1064         1065 

No.  PRICE  POST. 

1055  Drawing-Pen,    with   joint   and   pin,    ivory   handle, 

4f-inch $1.25  $0.10 

1056  Drawing-Pen,    with  joint   and   pin,    ivory  handle, 

5£-inch 1.40  .10 

1057  Drawing-Pen,    with   joint    and   pin,   ivory   handle, 

Gfinch 1.60  .10 

1060     Railroad  Pen,  without  joints,  ivory  handle,  6-inch ..  2.50  .10 


308 


W.  &  L.  E.   GURLEY,    TROY, 


No. 
1062 

1064 
1065 


PRICE       POST. 


1067 
1068 


1069 


1070 


1071 
1072 


Railroad  Pen,  with  joints  in  blades  and  shanks,  im- 
proved pattern,  ivory  handle,  5^-inch $3.00 

Dotting- Pen,  one  wheel,  ivory  handle,  6-inch 1.85 

Dotting-Pen,  six  wheels,  improved  pattern,  with  ink 

reservoir,  ivory  handle,  6-inch 3.75 


$0.10 
.10 

.10 


1067 

Beam-Compass  Furniture,  with  two  steel  points,  pen, 

pencil  and  needle  points,  in  morrocco  case 8.00 

Beam-Compass  Furniture,  with  micrometer  adjust- 
ment, two  steel  points,  pen,  pencil  and  needle 
points,  and  wheel  attachment  to  stand  alone  ;  all 
in  morocco  case 13.00 

Hardwood  Bars  for  No.  1067  Beam-Compass, 

24  30  36  48  inches  long. 

Each,  $0.25      $0.30      $0.35      $0.50 
Postage,  .10          .12          .15          .20 

Beam-Compasses,  18-inch,  in  two  German  silver 
bars,  with  two  steel  points,  pen,  pencil  and  needle 
points 10.50 

Beam-Compasses,  24-inch,  three  bars,  with  two  steel 

points,  pen,  pencil  and  needle  points 11.75 

Beam-Compasses,  36-inch,  three  bars,  with  two  steel 

points,  pen,  pencil  and  needle  points 15,25 


.20 


.30 


.20 
.25 
.30 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 


309 


1075  1079 

No.  PRICE        POST. 

1074  Proportional  Dividers,  7J-inch.  divided  for  lines  .  .  .     $8.00     $0.15 

1075  Proportional  Dividers,  74-inch,  divided  for  lines  and 

circles..  9.00         .15 


310  W.  &>  L.  E.   GURLEY,    TROY,  N.    Y. 

No.  PRICB       POST. 

1076     Proportional  Dividers,  8f -inch,  divided  for  lines  and 

circles,  and  with  rack  and  pinion  movement $12.50     $0.18 

1078  Proportional  Dividers,  9-inch,  divided  for  lines  and 

circles,  and  with  micrometer  screw 14.00         .20 

1079  Proportional    Dividers,    9-inch,     divided   for    lines, 

circles,   planes,   and  solids,  and   with  micrometer 

screw 16.50         .20 

Morocco  Cases  for  Proportional  Dividers  : 

To  fit  Dividers  Nos.  1074,  1075 1.00         .10 

No.    1076 1.40         .12 

"        Nos.  1078,  1079 1.60         .15 

1084  Polar  Planimeter,  German  silver,  best  quality,  meas- 
uring up  to  10  square  inches,  in  mahogany  case, 
with  printed  directions 16.50  .25 

1086  Polar  Planimeter,  German  silver,  best  quality,  meas- 
uring up  to  100  square  inches,  in  morocco  case, 
with  printed  directions 19.00  .26 

1088  Polar  Planimeter,  German  silver,  best  quality,  meas- 
uring up  to  450  square  inches.  Also  indicates 
square  feet  and  square  centimeters.  In  morocco 
case,  with  printed  directions 28.50  .35 

1090  Polar  Planimeter,  German  silver,  with  the  tracer- 
arm  graduated  nearly  its  entire  length  and  with 
vernier.  Easily  adjusted  to  any  desired  scale.  In 

mahogany  box,  with  printed  directions 33.50         .75 

By  means  of  the  Polar  Planimeter   a   person  can  ascertain  the  area  of 

any  planimetrical  figure  more  accurately  and  in  less  time  than  the   most 

experienced  mathematician  could  calculate  it. 

The  Planimeters  mentioned  above  are  the  favorite  styles  and  the  best  quality. 
We  can  furnish  cheaper  Planimeters  to  order  only,  but  do  not  keep  them  in  stock. 

EMPTY    CASES   FOR    DRAWING-INSTRUMENTS 

WITH  TRAY  FITTED  COMPLETE,  AND  WITH   LOCK.    SPACE  UNDER 
TRAY  FOR   SUNDRIES 

MAHOGANY  CASES  FITTED,  MOROCCO  CASES  FITTED, 

WITH  TRAY  WITHOUT  TRAY 

No.  Size  Plain        Polished      Postage  Price         Postage 

1092 8x3^  inches  $2.50  $3.25  $0.20  $2.25  $0.15 

1093 8x4  inches  2.75  3.50  .20  2.50  .15 

1094 8x5  inches  3.00  3.75  .25  2.75  .18 

1095 9x5  inches  3.25  4.00  .30  3.00  .18 

1096 10x6  inches  4.00  5.00  .35  4.00  .20 

1097 11x7  inches  4.75  5.75  .50  4.50  .25 

1098 13x7  inches  5.75  7.25  .75  5.00  .50 

Other  sizes  made  to  order. 


W.  6-  L.  E.   GURLEY,   TROY,  N.    Y.  311 


1086 


1088 


See  page  310. 


312  W.  &  L.  E.   GURLEY,   TROY,  N.    K 

SETS   OF   EXTRA   FINE   SWISS    DRAWING- 
INSTRUMENTS   IN   CASES 

No.  PRICE  POST. 

1100  Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1005  ;  Compasses,  No. 

1019  ;  Bow-pen,   No.   1034  ;   Drawing-pen,  No. 

1055  ;  Box  of  Leads $13.00  $0.16 

1102  Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1008  ;  Compasses,  No. 

1024  ;  Bow-pen,  No.  1041  ;  Drawing-pens,  Nos. 

1055  and  1057  ;  Box  of  Leads 17.00         .20 


1104 

1104  Morocco  Case,  containing: 

Hairspring  Dividers,  No.  1008  ;  Compasses,  No. 
1024;  Bow-spacer,  No.  1039;  Bow-pen,  No. 
1041  ;  Bow-pencil,  No.  1042 ;  Drawing-pens, 
Nos.  1055  and  1057  ;  Box  of  Leads 22.00  .25 

1105  Polished  Mahogany  Box,  with  lock  and  tray,  containing  : 

Hairspring  Dividers,  No.  1008  ;  Compasses,  Nos. 
1019  and  1024  ;  Drawing-pens,  Nos.  1055  and 
1056  ;  Box  of  Leads 21.00  .40 

1106  Polished  Mahogany  Box,  with  lock  and  tray,  containing  : 

Plain  Dividers,  No.  1003  ;  Hairspring  Dividers, 
No.  1008;  Compasses,  Nos.  1018  and  1022; 
Bow-spacer,  No.  1033 ;  Bow-pen,  No.  1034 ; 
Bow-pencil,  No.  1035  ;  Drawing-pens,  Nos.  1055 
and  1056  ;  Box  of  Leads.  .  27.00  .46 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y. 


313 


SUPERIOR   SWISS    DRAWING-INSTRUMENTS, 
WITH   PERFECT   PIVOT-JOINTED   HEADS 


1112  1  116 

No. 

1110  Plain  Dividers,  3^-inch 

1111  Plain  Dividers,  4^-inch 

1112  Plain  Dividers,  5-inch 
1114     Hairspring  Dividers,  3^ -inch 


314 


W.  6-  L.  E.   GURLEY,   TROY,  N. 


No.  PRICE       POST. 

1115  Hairspring  Dividers,  ±\ -inch $3.00     $0.12 

1116  Hairspring  Dividers,  5-inch 3.25         .12 

1119  Compasses,    3^ -inch,    with    fixed   needle   and    pen 

points 3.35         .10 

1120  Compasses,  3^-inch,   with  fixed  needle  and   pencil 

points 3.35  .10 

1.122  Compasses,  3^-inch,  with  fixed  needle  point,  and 

pen  and  pencil  points 5.00  .12 

1124  Compasses,  3^ -inch,  with  fixed  needle  point  with 

hairspring,  and  pen  and  pencil  points 6.00  .12 

1126  Compasses,  4£  -inch,  with  fixed  needle  point,  pen 

and  pencil  points  and  lengthening  bar. 6.25  .15 

1128  Compasses,  4^-inch,  with  fixed  needle  point  with 

hairspring,  pen  and  pencil  points  and  lengthening 

bar 7.25  .15 

1130  Compasses,  5^ -inch,  with  fixed  needle  point,  pen 

and  pencil  points  and  lengthening  bar 6.50  .15 

1132  Compasses,  5£  -inch,  with  fixed  needle  point  with 

hairspring,  pen  and  pencil  points  and  lengthening 

bar..  7.50         .16 


1135 


1  137 


1135  Steelspring  Bow-spacer,  3-inch,  with  metal  handle. 
1135B  Steelspring  Bow-.spacer,  3^-inch,  with  metal  handle. 

1136  Steelspring  Bow-spacer,  3-inch,  with  needle  points 

and  metal  handle ..." 

1137  Steelspring  Bow-pen,  3-inch,  with  metal  handle  . . 


1  138 

1.50 
1.80 

2.25 
2.25 


,10 

.10 

,10 
,10 


W.  &•>  L.  E.    GURLEY,    TROY,  N.    K  315 


1  132 


1  142 


1143 


For  prices,  see  pages  314  and  316. 


316  W-  &  L.  E.   GURLEY,    TROY,  N.    Y. 

No.  PRICE  POST. 
1137B  Steelspring  Bow-pen,  3^-inch,  with  metal  handle.  .  $2.50  $0.10 
1138  Steelspring  Bow-pencil,~3-inch,  with  metal  handle  .  -2.25  .10 
1138B  Steelspring  Bow-pencil,  3^-inch,  with  metal  handle.  2.50  .10 
1140  Steelspring  Bow-spacer,  3^-inch,  with  wheel  adjust- 
ment   2.00  JO 

1142  Steelspring  Bow-pen,   3^-inch,   with   wheel  adjust- 

ment         2.75         .10 

1143  Steelspring  Bow-pencil,  3^-inch,  with  wheel  adjust-  • 

ment 2.75         .10 

1147  Drawing-pen,    with    spring    blade,    ebony   handle, 

4^-inch 1.10         .10 

1148  Drawing-pen,    with    spring   blade,    ebony   handle, 

5-inch 1.20         .10 

1149  Drawing-pen,    with    spring   blade,    ebony    handle, 

Scinch 1.35         .10 


CASES   OF   SWISS    DRAWING-INSTRUMENTS 
WITH    PIVOT-JOINTED    HEADS 

1161     Morocco  Case,  containing  . 

Hairspring  Dividers,  No.  1115;   Compasses,  No. 

1126;   Drawing-pen,  No.  1148;  Box  of  Leads..    $12.00     $0.15 


1162 

1162  Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1114  ;  Compasses,  Nos. 
1119  and  1120  ;  Drawing-pen,  No.  1147  ;  Box  of 
Leads 12.00  .15 

1163  Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1115  ;  Compasses,  No. 
1126  ;  Bow-pen,  No.  1137  ;  Drawing-pens,  Nos. 
1147  and  1148  ;  Box  of  Leads ,  16,00  .20 


W.  &  Z.  E.   GURLEY,    TROY,  N.    Y.  317 

No.  PRICE        POST. 

1164  Morocco  Case,  containing : 

Hairspring  Dividers,  No.  1116;  Compasses,  Nos. 
1124  and  1130;  Drawing-pens,  Nos.  1147  and 
1148 ;  Box  of  Leads $20.00  |0.20 

1165  Morocco  Case,  containing : 

Hairspring  Dividers,  No.  1116  ;  Compasses,  No. 
1130;  Bow-spacer,  3^-inch ;  Bow-pen,  3^-inch; 
Bow-pencil,  3^-inch;  Drawing-pens,  Nos.  1147 
and  1148  ;  Box  of  Leads 21.50  .25 


1165-1166 

1166  Morocco  Case,  containing: 

Hairspring  Dividers,  No.  1115;  Compasses,  No. 
1126;  Bow-spacer,  No.  1135;  Bow-pen,  No. 
1137;  Bow-pencil,  No.  1138;  Drawing-pens, 
Nos.  1147  and  1148  ;  Box  of  Leads 20.00  .20 

1167  Morocco  Case,  containing : 

Hairspring  Dividers,  No.  1116;  Compasses,  Nos. 
1124  and  1130;  Bow-pen,  No.  1137;  Drawing- 
pens,  Nos.  1147,  1148,  and  1149;  Box  of  Leads  24.00  .26 

1168  Folding  Pocket  Case  with  flexible  flaps  (see  page 

323),  and  containing  same  instruments  as  in  set 

No.  1166 21.25  .20 

11 69 A  Folding  Pocket  Case  with  flexible  flaps,  and  con- 
taining same  instruments  as  in  set  No.  1165 22.75  .25 

1169B  Same  outfit  as  No.  1169A,  but  with  hairspring 

attachment  on  large  Compass 23.75  .25 


318 


W.  &  Z.  E.    GURLEY,   TROY,  N.    K 


ALTENEDER'S   PATENT    JOINT   GERMAN    SILVER 
AND   STEEL    DRAWING-INSTRUMENTS 

WARRANTED    GENUINE 

The  excellence  of  these  instruments  consists  in  the  joints  of  the 
dividers  being  so  constructed  as  to  prevent  any  irregular  motion  when 
the  legs  are  opened  or  closed,  also  in  the  general  care  with  which  the 
instruments  are  finished.  All  the  pens  are  well  made  and  pointed. 


No. 

1170 

1171 

1172 

1174 

1175 

1176 

1180 

1181 
1182 
1183 


Alteneder's 
Patent  Joint 


Knuckle- 
joints 


Clamp- 
Holders 


Plain  Dividers,  3|-inch 

Plain  Dividers,  4^-inch 

Plain  Dividers,  5-inch 

Hairspring  Dividers,  3^-inch 

Hairspring  Dividers,  4^ -inch 

Hairspring  Dividers,  5-inch 

Compasses,  3^-inch,  with  fixed  needle  and  pen 

points 

Compasses,  3^-inch,  with  fixed  needle  and  pencil 

points 

Compasses,  4^-inch,  with  fixed  needle  and  pen 

points 

Compasses,  4^-inch,  with  fixed  needle  and  pencil 

points 

See  cuts  on  page  319. 


Clamp- 
Sockets 

PRICE 
$2.26 

2.50 

2.50 

3.50 

3.75 

4.00 

4.00 
4.00 
4.50 
4.50 


POST. 

$0.10 
.12 
.12 
.10 
.12 
.12 

.10 
.10 
.12 
.12 


W.  &>  L.  E.    GURLEY,    TROY,  N.    Y. 


319 


1171 


1175 


1  1  82  1  1  83 

For  prices,  see  pages  318  and  321. 


1187 


320 


.  &>  L.  E.   GURLE\\    TROY,  N.    K 


1190 


1197 

For  prices,  see  page  321. 


1  198 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y. 


No. 

1184  Compasses,    5£-inch,    with   fixed   needle   and    pen 

points  ................................... 

1185  Compasses,   5-J-inch,   with  fixed  needle  and  pencil 

points  .................................... 

1186  Compasses,   3^-inch,   with  fixed  needle    point,   and 

pen  and  pencil  points  ....................... 

1187  Compasses,   3^-inch,   with  fixed  needle  point  with 

hairspring,  and  pen  and  pencil  points  .......... 

See  cut  of  No.  1187  on  page  319. 

1188  Compasses,  4^  -inch,  with  fixed  needle  point,  and  pen 

and  pencil  points  and  lengthening  bar  .......... 

1189  Compasses,   4£-inch,   with  fixed  needle    point  with 

hairspring,  and  pen  and  pencil  points  and  length- 
ening bar  ................................. 

1190  Compasses,   5^  -inch,   with   fixed   needle  point,   pen 

and  pencil  points  and  lengthening  bar  .......... 

1191  Compasses,   5£  -inch,   with   fixed  needle  point  with 

hairspring,  pen  and  pencil  points  and  lengthening 
bar  .......  ,  ............................... 

1195  Steelspring  Bow-spacer,  metal  handle,  3|-inch  .... 

1196  Steelspring  Bow-spacer,  needle  points,  metal  handle, 

31  -inch  ..............................  ..... 

1197  Steelspring  Bow-pen,   needle  poirtf,   metal   handle, 


1198     Steelspring  Bow-pencil,  needle  point,  metal  handle, 
3J-inch  ................................... 

See  cuts  of  Nos.  1190  to  1198  on  page  320. 


321 

PRICE 

POST. 

$5.00 

$0.12 

5.00 

.12 

6.00 

.12 

7.50 

.12 

7,25 

.14 

8.75 

.14 

7.50 

.15 

9.00 
1.75 

.15 
.10 

2.50 

.10 

2.50 

.10 

2.50 

.10 

1206 

1206  Drawing-pen,    with    spring    blade,    ebony   handle, 

4i-inch 1.40         .10 

1207  Drawing-pen,    with    spring    blade,    ebony   handle, 

5-inch •      1.65         .10 

1208  Drawing-pen,    with    spring    blade,    ebony   handle, 

5finch 1.90         .10 

1209  Drawing-pen,    with    patent    spring    hinge,     ebony 

handle,  5-inch 2.90         .10 

1210  Railroad-pen,  ebony  handle,  5-inch 3.50         .10 

1211  Swivel  Curve-pen,  spring  blade,  hollow  metal  handle.        2.00         .10 

1212  Pricker,  with  removable  needle  point,  ebony  handle.  .        1.00         .10 
1214     Nickel -plated  case,  for  leads 15         .02 


322  IK  &  L-   £>    GURLEY,    TROY,  N.    V. 

ALTENEDER'S  PATENT  JOINT  DRAWING-INSTRU- 
MENTS  IN   MOROCCO    CASE 

No.  PRICE  POST. 

1220  Morocco  Case,  containing  : 

Compasses,  Nos.  1180  and  1181  ;  Drawing-pen, 

No.  1206  ;  Box  of  Leads $10.75  $0.16 

1222  Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1175  ;  Compasses,  No. 

1188;  Drawing-pen,  No.  1207;  Box  of  Leads..  14.25  .18 
1224  Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1175  ;  Compasses,  No. 

1189  ;  Bow-pen,   No.   1197  ;   Drawing-pen,  No. 

1207  ;  Box  of  Leads 18.60         .20 


1225 

1225     Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1176;  Compasses,  No. 
1190;  Bow-spacer,  No.  1195;  Bow-pen,  No. 
1197;  Bow-pencil,  No.  1198;  Drawing-pens, 
Nos.  1206  and  1207  ;  Box  of  Leads 23.50  .20 

1227  Morocco  Case,  containing  : 

Hairspring  Dividers,  No.  1176;  Compasses,  No. 
1191;  Bow-spacer,  No.  1195;  Bow-pen,  No. 
1197;  Bow-pencil,  No.  1198;  Drawing-pens, 
Nos.  1206  and  1207  ;  Box  of  Leads 25.00  .25 

1228  Morocco  Case,  containing : 

Hairspring  Dividers,  No.  1176  ;  Compasses,  Nos. 
1186  and  1190;  Bow-spacer,  No.  1195;  Bow- 
pen,  No.  1197;  Bow-pencil,  No.  1198;  Drawing- 
pens,  Nos.  1206  and  1207  ;  Box  of  Leads 30.00  .30 


W.  &  L.  E.   GURLFA\   TROY,  N.    K  323 


1230 

No.  PRICK        POST. 
1230     Folding  Pocket  Case,  with  flexible  flaps,  and  con- 
taining same  instruments  as  in  set  No.  1225 $24.75     $0.20 

1232     Empty  Folding  Pocket  Case,  with 
flexible   flaps,  and  fitted  to  re- 
ceive from  five  to  twelve  pieces 

of    drawing-instruments ;  price,  PRICK  POST. 

according  to  size  of  case. ......   $3.00  to  $4.00     $0.12  to  $0.20 

Folding  Pocket  Cases  furnished,  instead  of  the  usual  Morocco  Cases, 
with  sets  Nos.  1220  to  1227,  at  an  extra.cost  of  $1.25,  and  with  set  No. 
1228  at  $1.50  extra. 


324 


W.  &•  L.  E.    GURLEY,   TROY,  N.   Y. 


BEST   GERMAN   DRAWING -INSTRUMENTS 

OF   FINE  GERMAN   SILVER   AND   STEEL 
For  prices  of  empty  cases  for  Drawing-Instruments,  see  page  3lO. 


1237  1241  1245  1247 

For  prices,  see  page  325.     Nos.  1237,  1241  and  1247  are  now  made  with  handles. 


W.  .&*  L.  E.    CUR  LEY,    TROY,  N.    Y. 


325 


PRICE  POST. 

Plain  Dividers,  3J-inch,  with  handle.  ., $0.70  $0.02 

Plain  Dividers,  5-inch,  with  handle 80  .03 

Plain  Dividers,  6-inch,  with  handle 1.00  .04 

Hairspring  Dividers,  3£  -inch,  with  handle 1.20  .10 

Hairspring  Dividers,  5-inch,  with  handle 1.50  .11 

Hairspring  Dividers,  0-inch,  with  handle 1.75  .12 

Compasses,  3^-inch,  with  pen,  pencil  and  needle 

points 2.50  .12 

Compasses,  5^-inch,  with  pen,  pencil  and  needle 

points  and  lengthening  bar 3.00  .15 


1250 


1251 


1253 


1257 


326 


W.  &>  L.  E.   GUR LEY,    TROY,  N.    Y. 


No.  PRICE  POST. 

1250  Pocket  Dividers,  5-inch,  with  sheath $1.50  $0.12 

1251  Three-legged  Dividers,  5-inch,  for  taking  off  three 

points -. 2.75  .13 

1253  Proportional  Dividers,  6^-inch,  divided  for  lines. .". .  2.50  .15 

1254  Proportional  Dividers,  7-inch,  for. lines  and  circles.  .  3.25  .15 

1255  Proportional  Dividers,  7-inch,  with  rack  movement 

and  divided  for  lines  and  circles 5.20  .15 

1257     Pocket  Compasses,  with  folding  points 5.00  .12 


1258 
1259 
1260 


1267 
1268 
1269 


1259 


1260 


Beam-Compass   Furniture,    with   pen,     pencil    and 

needle  points,  with  tangent  adjustment,  in  case  .  .  5.00  .16 
Beam-Compass   Furniture,    with    pen,     pencil    and 

needle  points,  in  morocco  case 6.00  .16 

Universal  Map-Measurer.     The  index -hand  registers 

inches  to  miles,  or  centimeters  to  kilometers 3.00  .12 

Steelspring  Bow-spacer,  ivory  handle,  3^-inch 1.00  .10 

Steelspring  Bow-pen,  ivory  handle,  3^-inch 1.25  .10 

Steelspring  Bow-pencil,  ivory  handle,  3^-inch 1.25  .10 


IV.  &  L.   E.   GURLEY,    TROY,  N.    Y.  327 


1267 


1268 


1269 


1270 

No.  PRICE        POST. 

1270     Set  of  three  Steel  Bows,  Nos.  1267,  1268  and  1269, 

in  morocco  case $4.20     $0. 16 

1275  Bow-spacer,  with  wheel  adjustment,   metal  handle, 

3^-inch 1.50         .10 

1276  Bow-pen,  with  wheel  adjustment,  metal  handle,  Si- 

inch .".       1.75         .10 

1277  Bow-pencil,  with  wheel  adjustment,   metal  handle, 

3^-inch 1.75         .10 

1278  Set  of  three  Steel  Bows,  Nos.  1275,  1276  and  1277, 

in  morocco  case, .  .  5.76         .16 


328 


W.  &  Z.  E.   GURLEY,   TROY,  N.    Y. 


1279 


1280  1282 

For  prices,  see  pages  327  and  329. 


1283 


IV.  &  L.  E.   GURLEY,    TROY,  N.    K 


329 


No.  PRICE  POST. 

1*27''     Spring  Bow-pen,  with  adjusting-screw $1.40  $0.10 

1280     Spring  Bow-pen,  with  pencil  leg  and  adjusting-screw  2.00  .10 

1282  Spring  Bow-pen,   with  adjustable  needle   point   for 

small  circles 2.50  .10 

1283  Spring  Bow-pen,   with  pencil    leg,    and   adjustable 

needle  point  for  small  circles 3.50  .10 

1284  Spring  Bow-pen,  with  spring' needle  point  for  small 

circles 2.75  .10 

1290     Drawing-pen,  without  joint,  ivory  handle,  44 -inch.  .  .35  .02 

1202     Drawing-pen,  without  joint,  ivory  handle,  5J| -inch.  .  .40  .03 

1204     Drawing-pen,  with  fine  joint,  ivory  handle,  \\  -inch.  .  .50  .02 

1295  Drawing-pen,  with  fine  joint,  ivory  handle,  5-inch ...  .55  .03 

1296  Drawing-pen,  with  fine  joint,  ivory  handle,  5^-inch.  ,  ,60  .03 


1294   1295 


1297 


1298 


1300 


1301 


330  W>  &  L>  E-   GURLEY,    TROY,  N.    Y. 

No.  PRICK        POST. 

1297  Drawing-pen,  with  fine  joint  and  pin,  ivory  handle, 

4£-inch $0.65     $0.02 

1298  Drawing-pen,  with  fine  joint  and  pin,  ivory  handle, 

5-inch TO         .03 

1299  Drawing-pen,  with  fine  joint  and  pin,  ivory  handle, 

5£— 6-inch 75         .03 

1300  Drawing-pen,    without     set-screw,     hollow     metal 

handle,  6£- inch 1.45         .10 

1301  Drawing-pen,    Swedish   pattern,    ebony  handle,   5- 

inch 75         .03 

1302  Drawing-pen,    Swedish   pattern,   ebony  handle,    6- 

inch 85         .03 

1303  Drawing-pen,   with  German  silver  blades,    for    red 

ink,  5-inch , 65         .03 

1304  Curve-pen,  ivory  handle,  4^ -inch 1.25         .10 

1305  Curve-pen,   swivel  blade,  hollow  metal  handle,   5- 

inch 1.50         .10 

1306  Drawing-pen,  for  heavy  border  lines,   ivory  handle, 

5£-inch 2.00         .10 

1307  Railroad-pen,  with  joints,  ivory  handle,  5^-inch  .  .  .        2.25         .10 

1308  Railroad-pen,  with  ivory  handle,  5J-inch,  will  draw. 

with  one  stroke  one  broad  or  two  parallel  lines  of 

the  same  or  different  widths 3.00         .10 

1309  Detail-pen,   with   broad  blades,    for    heavy   border 

lines,  ebony  handle,  6|--mch 1.00  .10 

1310  Pricker,  ivory  handle 1.20  .10 

1312     Tracer,  ivory  handle 90  .02 

1314     Dotting-pen,  one  wheel,  ivory  handle,  5-inch 1.00  .03 

1316     Dotting-pen,  with  six  wheels,  extra  fine,  in  morocco 

case 3.75         .12 

The  outer  wheel  is  rolled  on  the  edge  of  a  ruler  and 
turns  the  ratchet  wheel,  which  causes  the  pen  to  move  up 
and  down.  The  flat  point  near  the  pen  must  slide  on  the 
paper. 

1318     Railroad  Curve-pen,  swivel  blades 4.25         .12 


W.  &  L.  £.    GURLEY,    TROY,  N.    Y. 


331 


1304          1305  1307  1308         1310        1312         1314- 

For  prices,  see  page  330. 


332 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 


CASES   OF  FINE  GERMAN  SILVER   INSTRUMENTS 

FOR   ENGINEERS,  ARCHITECTS  AND   MACHINISTS 


No. 
1880 


1331 


1333 


1334 


1335 


1339 


1330 


PRICE        POST. 


Morocco  Case,  containing : 

Compasses,  No.  1245;  Drawing-pen,  No.  1294; 

Box  of  Leads $3.25 

Morocco  Case,  containing : 

Plain  Dividers,  No.  1235;  Compasses,  No.  1245; 

Drawing-pen,  No.  1294 ;  Box  of  Leads 4.00 

Morocco  Case,  containing: 

Plain  Dividers,   No.   1237;   Compasses,  5.] -inch, 

with  fixed  needle  point,  pen  and  pencil  points; 

Drawing-pen,  No.  1295 ;  Box  of  Leads 3.50 

Morocco  Case,  containing : 

Plain  Dividers,   No.   1237;   Compasses,  5i-inch, 

with  fixed  needle  point,   pen  and  pencil  points ; 

Bow-pen,   No.   1268;    Drawing-pen,    No.   1295; 

Box  of  Leads 4.75 

Morocco  Case,  containing : 

Plain  Dividers,  No.  1237  ;  Compasses,  No.  1247  ; 

Drawing-pen,  No.  1299  ;  Box  of  Leads 5.00 


$0.12 


.1:: 


.15 


.18 


1339 
Morocco  Case,  containing : 

Plain  Dividers,  No.  1237;  Compasses,  No.  1247; 
Bow-pen,  No.  1268 ;  Drawing-pen,  No.  1299  ; 
Box  of  Leads 


6.60 


.18 


W.  &•  L.  E.   CURLED   TROY',  M   Y. 


333 


No. 
1840 


1341 


1342 


1340 


PRICE        POST. 


Morocco  Case,  containing : 

Plain  Dividers,  No.  1237 ;  Compasses,  Nos.  1245 
and  1247;  Drawing-pens,  Nos.  1297  and  1299; 
Box  of  Leads $  8.75  $0.20 

Morocco  Case,  containing : 

Plain  Dividers,  No.  1237  ;  Compasses,  Nos.  1245 
and  1247;  Bow-pen,  No.  1268;  Drawing-pens, 
Nos.  1297  and  1299  ;  Box  of  Leads 10.00 


Morocco  Case,  containing : 

Plain  Dividers,  No.  1241 ;  Compasses,  No.  1247 ; 
Bow-spacer,  No.  1267;  Bow-pen,  No.  1268; 
Bow-pencil,  No.  1269  ;  Drawing-pens,  Nos.  1297 
and  1299  ;  Box  of  Leads 10.00 


.20 


.20 


1345 

1345     Polished  Mahogany  Box,  with  lock  and  tray,  con- 
taining : 

Plain  Dividers,  No.  1237 ;  Hairspring  Dividers, 
No.  1241;  Compasses,  Nos.  1245  and  1247; 
Bow-pen,  No.  1279;  Drawing-pens,  Nos.  1297 
and  1299  ;  Box  of  Lead= 14.50 


.45 


334 


L.  E.   GURLEY,   TROY,  N.    Y. 


No.  PRICB       POST. 

1346     Polished  Mahogany  Box,  with  lock  and  tray,  con- 
taining : 

Hairspring  Dividers,  No.  1241 ;  Compasses,  Nos. 
1245  and  1247  ;  Proportional  Dividers,  No.  1253  ; 
Bow-pen,  No.  1268;  Drawing-pens,  Nos.  1297 
and  1299  ;  Box  of  Leads $16.00  $0.60 

1348     Polished  Mahogany  Box,   with  lock  and  tray,  con- 
taining : 

Hairspring  Dividers,  No.  1241 ;  Compasses,  No. 
1247;  Proportional  Dividers,  No.  1253;  Bow- 
spacer,  No.  1267;  Bow-pen,  No.  1268;  Bow- 
pencil,  No.  1269;  Railroad-pen,  No.  1307; 
Curve-pen,  No.  1304;  Drawing-pens,  Nos.  1297, 
1299  and  1301  ;  Box  of  Leads 20.00  .56 

1352     Polished  Mahogany  Box,   with  lock  and  tray,  con- 
taining : 

Plain  Dividers,  No.  1237 ;  Hairspring  Dividers, 
No.  1241;  Compasses,  Nos.  1245  and  1247; 
Proportional  Dividers,  No.  1255 ;  Bow-spacer, 
No.  1275;  Bow-pen,  No.  1276;  Bow-pencil, 
No.  1277;  Railroad-pen,  No.  1308;  Curve-pen, 
No.  1305;  Drawing-pens,  Nos.  1294,  1298  and 
1301  ;  Beam-compass,  No.  1259  ;  Box  of  Leads.  35.00  .75 

The  Dividers  and  Compasses  in  sets  Nos.  1330  and  1352  are  now 
made  with  handles. 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y.  335 

SETS    OF    PIVOT-JOINT    INSTRUMENTS    OF    BEST 
GERMAN   MAKE 

FINE  GERMAN  SILVER  AND  STEEL 
No.  PRICE        POST. 

1355  Morocco  Case,  containing : 

Plain  Dividers,  5-inch ;  Compasses,  5^-inch,  with 
fixed  needle  point,  pen  and  pencil  points  and 
lengthening  bar  ;  Drawing-pen;  Box  of  Leads. ..  $  8.00  $0.15 

1356  Morocco  Case,  containing  : 

Plain  Dividers,  3^-inch ;  Compasses,  3£-inch, 
with  fixed  needle  and  pen  points ;  Compasses, 
3^-inch,  with  fixed  needle  and  pencil  points; 
Drawing-pen ;  Box  of  Leads 9.00  .15 

1357  Morocco  Case,  containing  : 

.  Plain  Dividers,  5-inch  ;  Compasses,  5^-inch,  with 
fixed  needle  point,  pen  and  pencil  points  and 
lengthening  bar ;  Bow-pen  ;  Drawing-pen  ;  Box 
of  Leads..  9.50  .18 


1358 


1358  Morocco  Case,  containing  : 

Hairspring  Dividers,  5-inch;  Compasses,  5^ -inch, 
with  fixed  needle  point,  pen  and  pencil  points  and 
lengthening  bar ;  Bow-spacer  ;  Bow-pen  ;  Bow- 
pencil  ;  two  Drawing-pens  ;  Box  of  Leads 12.50  .20 

1359  Folding  Pocket  Case,   with  flexible  flaps,  see  page 

32-3,   and  containing  same  instruments   as    in    set 

No.  1358...  13.75         .20 


336 


W.  &-L.  E.   GURLRY,    TROY,  N.    Y. 


SETS     OF     GERMAN     SILVER     DRAWING -INSTRU- 
MENTS  FOR   SCHOOL   USE 


1365 


No  PRICE 

1365     Leather  Case,  containing  : 

Plain  Dividers,  5-inch;  Compasses,  5^  -inch,  with 
fixed  needle  point,  pen  and  pencil  points  and 
lengthening  bar  ;  Drawing-pen;  Box  of  Leads.  .  $3.00 


POST. 


1367 

1367     Leather  Case,  containing  : 

Plain  Dividers,  5-inch  ;  Compasses,  5.] -inch,  with 
fixed  needle  point,  pen  and  pencil  points  and 
lengthening  bar  ;  Bow-pen  ;  Drawing-pen  ;  Box 
of  Leads.  . 


4.00         .15 


W.  &  Z.  E.   GURLEY,   TROY,  N.    Y. 


337 


1369 

No.  PRICB       POST. 

1369     Leather  Case,  containing  : 

Plain  Dividers,  5-inch ;  Compasses,  5} -inch,  with 
fixed  needle  point,  pen,  pencil  and  lengthening 
bar  ;  Bow-spacer  ;  Bow-pen  ;  Bow-pencil ;  Draw- 
ing-pen ;  Box  of  Leads $  6.00  $0.18 

1371      Leather  Case,  containing  : 

Plain  Dividers,  5-inch  ;  Compasses,  3^-inch,  with 
fixed  needle  point,  pen  and  pencil  point ;  Com- 
passes, 5|-inch,  with  fixed  needle  point,  pen, 
pencil  and  lengthening  bar ;  Bow-spacer ;  Bow- 
pen  ;  Bow-pencil ;  two  Drawing-pens ;  Box  of 
Leads.  .  9.00  .20 


338 


W.  &•  L.  E.    GURLEY,    TROY,  N.    Y. 


BRASS    DRAWING-INSTRUMENTS 

FOR  SCHOOL  USE 


No. 
1376 
1376 
1378 
1379 


1386 

Plain  Dividers,  rivet-joint,  4-inch 
Plain  Dividers,  rivet-joint,  5-inch 
Plain  Dividers,  screw-joint,  4-inch. 
Plain  Dividers,  screw-joint,  5-inch. 


W.  <Sr-  L.  E.   GURLEY,    TROY,  N.    Y.  339 

No.                                                                                                                 TRICE  POST. 

1385  Compasses,  4^ -inch,  with  pen  and  pencil  points  and 

lengthening  bar $0.50  $0.05 

1386  Compasses,  4|-inch,  with  fixed  needle  point,    pen 

and  pencil  points  and  lengthening  bar .60  .05 

1387  Compasses,  6-inch,  with  pen  and  pencil  points  and 

lengthening  bar .65  .08 

1388  .  Compasses,  6 -inch,  with  fixed  needle  point,  pen  and 

pencil  points  and  lengthening  bar .76  .08 

1389  Spring  Bow-pen,  with  needle  point,  3-inch 60  .02 

1391     Roulette,  with  three  wheels,  for  dotting  lines 75  .03 

1393     Proportional  Dividers,  6£-inch,  divided  for  lines  ...        1.50  .13 

1395  Drawing-pen,  wood  handle .15  .02 

1396  Drawing-pen,  bone  handle 20  .02 

1400  Wood  Dividers,  with  crayon  holder,  12-inch 1.00  .15 

1401  Wood  Dividers,  with  crayon  holder,  15-inch 1.25  .18 

1402  Wood  Dividers,  with  crayon  holder,  18-inch 1.50  .20 


CASES   OF   BRASS    DRAWING -INSTRUMENTS 

FOR  SCHOOL  USE 

1405  Rosewood  Box,  containing  : 

Plain  Dividers,  4^-inch ;  Compasses,  4-inch,  with 
pen  and  pencil  points ;  Compasses,  6-inch,  with 
pen  and  pencil  points  and  lengthening  bar  ;  Draw- 
ing-pen ;  Brass  and  Horn  Protractors  ;  Wood  Rule  $2.00  $0.23 

1406  Rosewood  Box,  with  lock  and  tray,  containing : 

Plain  Dividers,  4^-inch  ;  Compasses,  4-inch,  with 
fixed  needle  point,  pen  and  pencil  points ;  Com- 
passes, 6-inch,  with  fixed  needle  point,  pen  and 
pencil  points  and  lengthening  bar ;  Drawing-pen ; 
Brass  and  Horn  Protractors  ;  Wood  Rule 3.00  .28 

1407  Rosewood  Box,   etc.,  same  as  No.  1406,  and  with 

addition  of  Spring  Bow-pen 3.75         .28 

1408  Rosewood  Box,  etc.,  same  as  No.  1406,  and  with 

addition  of  Spring  Bow-pen,  Proportional  .Divid- 
ers, Triangle  and  Irregular  Curve,  and  omitting 
Brass  Protractor 6.50  .36 


340  W.  &>  L.   E.   CUR  LEY,    TROY,  N.    Y. 

NICKEL-PLATED   DRAWING -INSTRUMENTS 


1413   1416 


1418 


1420 


1425  AND  1427 

For  prices  of  Nos.  1413  to  1427,  see  page  341. 


W.  &>  L.  E.   GURLEY,    TROY,  Ar.    K  341 

NICKEL-PLATED     BRASS     DRAWING-INSTRU- 
MENTS 

FOR  SCHOOL  USE.    SEE  PAGE  340 

No.                                                                                                            PRICB  POST. 

1410  Plain  Dividers,  rivet-joint,  4i-inch $0.20  $0.02 

1411  Plain  Dividers,  rivet-joint,  5^-inch ,,,       .25  .03 

1413  Plain  Dividers,  screw-joint,  4^-inch 25  .02 

1414  Plain  Dividers,  screw-joint,  5^-inch 30  .03 

1416  Compasses,  4-i-inch,  with  pencil  point 35  .03 

1418  Compasses,  4|-inch,  with  pen  and  pencil  points 50  '.04 

1420  Compasses,  4^-inch,  with  pen  and  pencil  j.oinl.3  and 

lengthening  bar 65         .05 

1425     Drawing-pen,  black  wood  handle,  5-inch 20         .03 

1427     Drawing-pen,  bone  h'andle,  5-inch 30         .03 

SETS   OF    NICKEL-PLATED    DRAWING-INSTRU- 
MENTS  IN   LEATHERETTE   CASES 

FOR  SCHOOL  USE 

1430  Case,  containing  : 

Compasses,  4^-inch,  with  pen  and  pencil   points  ; 

Box  of  Leads  ;    Color-saucer , $0.65     $0.08 

1431  Case  containing  : 

Compasses,  4^-inch,  with  pen  and  pencil  points  ; 
Drawing-pen ;  Box  of  Leads ;  Color-saucer ; 
Protractor,  Ruler  and  Triangle 85  .10 


1433 


342 


W.  &  L.   E.   GURLEY,    TROY,  N.    V. 


No. 
1433 


PRICE        POST. 
Case,  containing : 

Plain  Dividers,  4-inch ;  Compasses,  4^-inch, 
with  pen  and  pencil  points ;  Drawing-pen  ;  Box 
of  Leads ;  Color-saucers ;  Protractor,  Ruler  and 
Triangle • $1.20  fO.15 


1436 


1436 


Case,  containing  : 

Plain  Dividers,  4-inch  ;  Compasses,  4^-inch,  with 
pen  and  pencil  points  and  lengthening  bar ; 
Spring  Bow-pen  ;  Drawing-pen  ;  Box  of  Leads  ; 
Color-saucers  ;  Protractor,  Ruler  and  Triangle.  ...  2.00 


.20 


W.  &  L.  E,   GURLEY,    TROY,  N.    Y. 


343 


PROTRACTORS 


EXTRA     FINE     SWISS     GERMAN     SILVER 
PROTRACTORS 


1442 


No. 
1440 

1441 
1442 
1443 


PRICE        POST. 


1445 

1446 
1447 
1450 


Protractor,  half-circle,  4-inch,  beveled  edge,   center 

on  outer  edge,  divided  to  1  degree $2.25 

Protractor,  half-circle,  5-inch,  divided  to  \  degrees.  .  3.35 

Protractor,  half-circle,  6-inch,  divided  to  \  degrees.  .  3.85 

Protractor,  half-circle,  G-inch,  divided  to  \  degrees.  .  4.75 


1446 


Protractor,   half-circle,   5-inch,  beveled    edge,   center 

on  inner  edge,  divided  to  \  degrees   

Protractor,  half-circle,  6-inch,  divided  to  \  degrees.  . 
Protractor,  half-circle,  6-inch,  divided  to  |  degrees.  . 
Protractor,  whole  circle,  5-inch,  divided  to  £  degrees 


4.35 
5.25 


$0.12 
.13 
.15 
.15 


$0.14 
.16 
.16 
.20 


344 


.  '&  L.  E.   CURLEY,    TROY,  N.    Y. 


No. 
1454 


EXTRA    FINE    SWISS   GERMAN   SILVER 
PROTRACTORS,  WITH    ARM    AND 
WITHOUT   VERNIER 

PRICE  POST. 
Protractor,  half-circle,  6-inch, 

with  horn  center  and  6-inch 

movable  arm,  divided  to  \ 

degrees $11.50  $0.20 

Protractor,  half-circle,  7-inch, 

with  horn  center  and  6-inch 

movable  arm,  divided  to  \ 

degrees ".      13.00         .25 


Length  of  arms  extending  over 

the  outer  edge  of 

Protractors 


For  Nos.  1460  and  1465,  5£-inch 
For  Nos.  1461,  1466,  1470,  6-inch 
For  Nos.  1462,  1467,  1473,  6^-inch 


1461 

EXTRA    FINE    SWISS    GERMAN    SILVER    PRO- 
TRACTORS, WITH    ARM    AND   VERNIER 

No.  PRICE        POST. 

1460  Protractor,    half-circle,   5^-inch,   with    horn    center 

and  movable  arm,  divided  to  .}  degrees,   vernier 

reading  to  3  minutes " $14.00     $0.20 

1461  Protractor,  half-circle,  8-inch,  divided  to  |  degrees, 

vernier  to  1  minute  .  .  17.00         .25 


W.  &>  L.  E.   GURLEY,   TROY,  N.    V. 


345 


No.  PRICE        POST. 

14(32     Protractor,  half-circle,  10-inch,  divided  to  J  degrees, 

vernier  to  1  minute |21.00     $0.35 

1465  Protractor,  whole  circle,  5^-inch,  with  horn  center 

and  movable  arm,  divided  to  ry  degrees,   vernier 

reading  to  8  minutes 17.00         .80 

1466  Protractor,  whole  circle,  8-inch,  divided  to  ]  degrees, 

vernier  to  1  minute 20.00         .35 

1467  Protractor,   whole   circle,   10-inch,  divided  to  |  de- 

grees, vernier  to  1  minute 23.00         .50 

1470  Protractor,  half-circle,  8-inch,  with  horn  center  and 
movable  arm,  divided  to  \  degrees,  vernier  to  1 

minute,  with  clamp  and  tangent  to  arm 23.00         .30 

1473  Protractor,  whole  circle,  8-inch,  with  horn  center 
and  movable  arm,  divided  to  \  degrees,  vernier  to 
1  minute,  with  clamp  and  tangent  to  arm 26.00  .40 

MAHOGANY   CASES   FOR   PROTRACTORS 

1476  Case  for  Protractors  Nos.  1454,  1455,  1460 $1.75     $0.25 

1477  Case  for  Protractors  Nos.  1461,  1462,  1465,  1470. ..     2.25         .35 

1478  Case  for  Protractors  Nos.  1466,  1467,  1473 3.00         .45 

LIMB-PROTRACTOR 

BRONZE  HEAD,  STEEL  BLADE,  VERNIER  TO  ONE  MINUTE 
Made  by  W.  &  L.  E.  Gurley 


VERTICAL  SECTION 
For  prices,  see  page  346. 


346 


W.  &  L.  K.   C  UK  LEY,    TROY,  N.    V. 


LIMB-PROTRACTOR 


BRONZE  HEAD,  STEEL   BLADE,  VER] 
No. 
1480  .  Limb-Protractor,  with  blade  24-inch. 
1481     Limb-Protractor,  with  blade  30-inch. 
1482     Limb-Protractor,  with  blade  36-inch. 
1483     Limb-  Protractor,  with  blade  42-inch. 
1484     Limb-  Protractor,  with  blade  48-inch. 

SIIER  TO  ONE  MINUTE 
PRICE 
Nickel-plated               *  8-00 

Nickel-plated.  .  . 
Nickel-plated.  .  . 
Nickel-plated.  . 
Nickel  -plated.  .  . 

...       8.75 
9.50 
.  .  .     10.25 
...     11.60 

W.  6-  /..   E.    G  UK  LEY,    TROY,  N. 


347 


No.  PRICE        POST. 

1480  Steel  Protractor,  divided  to  1  degree,  vernier  to  5 
minutes,  S^-inch  blade.  It  is  used  with  the  T- 
rule  or  straight-edge.  Very  convenient  in  dividing 
circles,  transferring  angles,  laying  off  angles  each 
side  of  a  line  without  resetting.  In  morocco  case  $  7.75  $0.35 
1488  Crozet  Protractor,  German  Silver,  8-inch,  half-circle, 
half-degrees,  vernier  to  1  minute.  In  mahogany 

case 40.00         .70 

The  Crozet  Protractor  we  can  recommend  as  the  best 
among  the  high-grade  protractors. 

It  is  used  with  the  T-rule  or  straight-edge.  The  feather- 
edge  is  set  to  the  starting-point  and  lines  produced  without 
puncturing  the  paper. 


DUFFIELD    PROTRACTOR 

Made  by  W.  &  L.  E.  Gurley. 

Made  of  transparent  celluloid,  with  two  parallel  scales  of  twenty 
parts  to  the  inch,  so  that  the  zero  line  can  be  set  parallel  to  meridian 
lines  drawn  on  the  paper. 


1490 

1490     Protractor,  half-circle,  6-inch,  divided  to  £  degrees.  .  $3.00 

1492     Protractor,  half-circle,  9-inch,  divided  to  J  degrees.  .  3.50 

1494     Protractor,  half-circle,  12-inch,  divided  to  \  degrees.  .  4.00 


GERMAN    SILVER   PROTRACTORS 

1500     German   Silver  Protractor,  4-inch,   half-circle,  whole 

degrees $0.50     $0.03 

1502  German  Silver  Protractor,    5-inch,    half-circle,    half- 

degrees. 85         .05 

1503  German    Silver    Protractor,    6-inch,    half-circle,    half- 

degrees 1.00         .07 


848 


W. 


Z.  E.   GURLEY,    TROY,  N.    K 


1510 

No.  PRICE         POST. 

150U     German      Silver      Protractor,     5-inch,     half-circle, 

beveled  edge,  half-degrees $1.25     $0. 13 

1510  German      Silver     Protractor,     6-inch,     half-circle, 

beveled  edge,  half-degrees 1.50         .15 

1511  German      Silver     Protractor,     7-inch,     half-circle, 

beveled  edge,  half-degrees 2.00         .18 


BRASS    PROTRACTORS 

1515  Brass  Protractor,  3^ -inch,  half-circle,  whole  degrees  $0.10  $0.02 

1516  Brass  Protractor,  4  -inch,  half-circle,  whole  degrees  .25  .03 

1517  Brass  Protractor,  4  -inch,  half-circle,  half-degrees. .  .35  .03 

1518  Brass  Protractor,  5  -inch,  half-circle,  half-degrees.  .  .50  .05 

1519  Brass  Protractor,  6  -inch,  half-circle,  half-degrees..  .60  .07 


OPAQUE   WHITE   CELLULOID    PROTRACTORS 

1525W     Celluloid  Protractor,  6-inch,  half-circle,    beveled 

edge,  half-degrees $3.00  $0. 1  :J 

1526W  Celluloid  Protractor,  8-inch,  half-circle,  beveled  * 

edge,  half-degrees 3.75  .15 

1527W  Celluloid  Protractor,  6-inch,  whole  circle,  beveled 

edge,  half-degrees 3. 75  .18 

1528W  Celluloid  Protractor,  8-inch,  whole  circle,  beveled 

edge,  half-degrees 5.00        .20 


W.  &  L.  E.   G UR LEY,    TROY,  N.    K  349 
TRANSPARENT   CELLULOID    PROTRACTORS 

No.                                                                                                                       PKICE  POST. 

1532  Celluloid     Protractor,    6-inch,    half-circle,    beveled 

edge,  half-degrees $3.00  $0.13 

1533  Celluloid     Protractor,    8-inch,    half-circle,    beveled 

edge,  half-degrees. .  .  . .. 3.75  .15 

1535  Celluloid    Protractor,   6-inch,   whole   circle,  beveled 

edge,  half-degrees 3.75  .18 

1536  Celluloid    Protractor,   8-inch,   whole  circle,  beveled 

edge,  half-degrees 5.00  .25 

TRANSPARENT  HORN  PROTRACTORS 

1540  Horn  Protractor,  4-inch,  half-circle,  whole  degrees     $  0.15  $0.02 

1541  Horn  Protractor,  5-inch,  half-circle,  half-degrees.  .            .25  .02 

1542  Horn  Protractor,  6-inch,  half-circle,  half-degrees. .            .30  .03 
1544     Horn  Protractor,  8-inch,  half-circle,  half-degrees.  .            .60  .05 

1547  Horn  Protractor,  5-inch,  whole  circle,  half-degrees         1.25  .     .12 

1548  Horn  Protractor,  6-inch,  whole  circle,  half-degrees         1.50  .14 


1550 

1550  Railroad  Curve  Protractor,  of  horn,  8-inch,  half- 
circle,  half-degrees,  with  circular  curves  from  ^ 
degree  to  8  degrees,  to  a  scale  of  400  feet  to  the 

inch $1.60 

1551 A  Ditto,  of  transparent  celluloid 2.25 

1551B  Railroad  Curve  Protractor,  of  transparent  celluloid, 
10-inch,  half-circle,  half-degrees,  with  circular 
curves  1°,  1£°,  2°,  2£°,  3°,  3£°,  4°,  5°,  6°,  7°, 
8°,  10°,  12°,  14°,  16°,  18°,  20°,  to  a  scale  of 
100  feet  to  the  inch 2.75 


$0.13 
.18 


350  W-  &  S~  £•   G  UK  LEY,    TROY,  N.    K 

PAPER    PROTRACTORS 

No.  PRICE 

1552  Protractor,    on   Bristol    Board,    5-inch,    half-circle, 

half-degrees 

1553  Protractor,    on    Bristol     Board,    6-inch,     half-circle, 

half-degrees .- 15 

1554  Protractor,    on    Bristol    Board,    5-inch,    half-circle, 

half-degrees,   and    diagonal    scale  to   inches   and 
T^th,  and  millimeter 15 

1555  Protractor,  on   Bristol   Board,  8-inch,  whole  circle, 

half-degrees 20 

1556  Protractor,  on  Bristol  Board,   18-inch,  whole  circle, 

quarter-degrees 40 

1558  Protractor,  on  Drawing  Paper,  18-inch,  whole  circle, 

quarter-degrees 30 

1559  Protractor,  on  Tracing  Paper,  13-inch,  whole  circle, 

quarter-degrees , .         .25 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y.  351 

SCALES 


IVORY   PROTRACTOR-SCALES 


No. 
1560 


1561 


1564 


1  56O    FRONT  SIDE 


PRICE        POST. 


Ivory  Rectangular  Protractor,  6  inches  long,  If 
inches  wide,  with  scales  as  follows  :  front  sides 
divided  around  edges  from  0  to  180  degrees  in 
single  degrees,  scales  of  \,  %,  f  and  1  inch  to  the 
foot,  and  scale  of  chords.  Reverse  side  scales  of 
30,  35,  40,  45,  50  and  60  parts  to  the  inch,  scale 
of  chords  and  diagonal  scale  of  inches  and  T^nths.  $1 . 50  $0. 1 2 

Ivory  Rectangular  Protractor,  6  inches  long  by  If 
inches  wide,  with  scales  as  follows  :  front  side, 
the  edge  divided  into  single  degrees  from  0  to  180 
degrees,  scales  of  J,  ±,  f,  \,  f,  f,  |,  and  1  inch 
to  the  foot,  and  scale  of  chords.  On  the  reverse 
side,  scales  of  30,  35,  40,  45,  50  and  60  parts  to  the 
inch,  scale  of  chords  and  diagonal  scale  of  y^ths. .  2.00  .12 

Ivory  Rectangular  Protractor,  6  inches  long  by  2 
inches  wide,  with  scales  as  follows:  front  side, 
the  edge  divided  in  \  degrees  from  0  to  180  degrees, 
scales  of  |,  \,  f,  f,  &  f,  j>  1,  Ife  1}  inches  to 
the  foot,  scale  of  chords,  and  line  of  40  parts  on 
lower  edge.  On  the  reverse  side,  scales  of  20,  25, 
30,  35^  40,  45,  50  and  60  parts  to  the  inch,  and 
diagonal  scale  of  T^ths 4.00  .13 

Ivory  Rectangular  Protractor,  6  inches  long  by  2^ 
inches  wide,  with  scales  as  follows  :  front  side, 
the  edge  divided  in  £  degrees  from  0  to  180  de- 
grees, scales  of  J,  },  f,  J,  f,  f,  |,  1,  1J,  1J,  If, 
\\  inches  to  the  fcibt,  scale  of  chords,  and  scale  of 
40  parts  on  the  lower  edge.  Reverse  side,  scales 
of  10,  15,  20,  25,  30,  35,  40,  45,  50  and  60  parts 
to  the  inch,  and  diagonal  scale  of  y^ths 4.50  .13 


352 


IV.  &  L.   E.   CUR  LEY,    TROY,   X.    Y. 


FLAT    BOXWOOD   AND   IVORY   SCALES 

No.  PKICH        POST. 

1;">70  Boxwood  Protractor,  6  inches  long,  If  inches  wide, 
divided  to  whole  degrees,  with  scales  J,  \,  f,  1 
inch,  diagonal  scale  and  scale  of  chords $0.85  $0.08 

1672     Boxwood  Scale,  6-inch,  for  school  use 15         .02 


1573 


1673     Ivory  Scale,  6-inch,  with  diagonal  and  chain-scales.  .  .85  .08 

1575  Boxwood  Sector-Scale,  6-inch,  opens  to  12-inch 1.00  .12 

1576  Ivory  Sector-Scale,  6-inch,  opens  to  12-inch 2.25  .15 

1577  Boxwood   Scale,   6-inch,   divided  |,  £,   J,  1  inch  to 

the  foot..,  .50  .03 


I\^\    ^    \ 

A    1   ,\    S   \ 

^"S           5.Q 

nrtT\\ 

*% 

ENGINE  DIVIDED 

8                         8 

9               8              OT             ST            tt 

1 

as          o» 

0           -j^ 

TJ.S.Si. 

UT/T/T//8//8//8 

108  I8i  ISLlHlSL  lot  IS9  1  <a  l>9 

Illllllilllllll/lll 

/''/TIlT'l'Ifli'll/'UJ 

1578 

1678     Boxwood  Scale,  12-inch,  divided  J,  ],  J,  1  inch  to 

the  foot 75 

1579  Boxwood  Scale,   18-inch,  divided  $,  \,  £,  1  inch  to 

the  foot «.     1.50 

1580  Boxwood  Scale,  24-inch,  divided  £,  \,  £,  1  inch  to 

the  foot 2.00 

1581  Ivory  Scale,  6-inch,  divided  £,   \,   $,   1   inch  to  the 

foot 2.00 

1582  Ivory  Scale,  12-inch,  divided  £,  },   ^,  1  inch  to  the 

foot.  . . ......: 3.00 

1583  Boxwood  Scale,  6-inch,  divided  f,  f,  1J,  3  inches  to 

the  foot..  50 


.06 
.18 
.22 
.12 
.14 
.03 


W.  &  L.  E.   GU-RLEY,    TROY,  N.    Y.  353 

No  PRICK       POST. 

1584  Boxwood  Scale,   12-inch,  divided  f,  f,  U,  3  inches 

to  the  foot , $0.75     $0.06 

1585  Boxwood  Scale,   18-inch,  divided  f,  f,  1£,  3  inches 

to  the  foot, 1.50         .18 

1586  Boxwood  Scale,  24-inch,  divided  f,  f,  1£,  3  inches 

to  the  foot 2.00         .22 

1587  Ivory  Scale,   6-inch,  divided  f,   £,   1£,  3    inches  to 

the  foot 2.00         .12 

1588  Ivory  Scale,   12-inch,   divided   f,  f,   \\  3  inches  to 

the  foot " 3.00         .14 

1590  Boxwood  White  Edge   Scale,  6-inch,  divided  J,  |, 

\,  1  inch  to  the  foot 75         .03 

1591  Boxwood  White  Edge  Scale,   12-inch,  divided  \,  \y 

%,  1  inch  to  the  foot 1.25         .14 

1594  Boxwood  White  Edge   Scale,  6-inch,  divided  f,  f, 

1J,  3  inches  to  the  foot 75         .03 

1595  Boxwood  White  Edge  Scale,  12-inch,  divided  f,  f, 

1J,  3  inches  to  the  foot 1.25         .14 

1604  Boxwood  Scale,  12-inch,  one  side  rounded,  the  other 

flat,  with  the  following  scales,  the  graduations  of 
which  are  all  brought  to  the  edge:  ^g,  J,  ^,  \, 
i  i  f,  I,  I,  1,  U,  U,  If,  2,  2i,  and  3  inches 
to  the  foot,  the  first  division  of  each  scale  subdi- 
vided into  12  parts 90  .06 

1605  Ivory  Scale,  12-inch,  divided  same  as  No.  1604 4.00         .14 

1610  Boxwood  School  Rule,  12-inch,  divided  ^  and  £  of 

an  inch 10         .03 

1611  Boxwood    School    Rule,    18-inch,    divided   £   of  an 

inch,  and  with  inlaid  brass  edges 35         .10 

1612  School  Rule,  12-inch,  beveled  edges,  divided  ^  of 

an  inch  and  millimeters 15         .05 

1613  School  Rule,  18-inch,  beveled  edges,  divided  ^  of 

an  inch  and  millimeters ..  .35         .10 


354  W-  &  I»  E,    GURLEY,    TROY,  N.    V. 

FLAT   BOXWOOD   CHAIN-SCALES 

r ^\\\\\\\\\YV\\\V\\\\Y\\\\\\^\\\\\V^WV^\\\\\\\\\\\\\\\\\\\\\  \ 

1618 

No.  PRICK      POST. 

1615  Boxwood  Scale,   6 -inch,  divided  10  and  50  parts  to 

the  inch $0.50    $0.03 

1616  Boxwood  Scale,  6-inch,  divided  20  and  40  parts  to 

the  inch 50        .03 

1617  Boxwood  Scale,  6-inch,  divided  30  and  60  parts  to 

the  inch 50         .03 

1618  Boxwood  Scale,  12-inch,  divided  10  and  50  parts  to 

the  inch 75         .06 

1619  Boxwood  Scale,  12-inch,  divided  20  and  40  parts  to 

the  inch 75         .06 

1620  Boxwood  Scale,  12-inch,  divided  30  and  60  parts  to 

the  inch 75         .06 

1627     Boxwood   Offset   Scales,    2-inch,   divided    like    Nos. 

1615  to  1617,  each 40         .02 

1632  Boxwood   White   Edge   Scale,    12-inch,    divided   10 

and  50  parts  to  the  inch 1.25         .14 

1633  Boxwood   White    Edge    Scale,    12-inch,    divided   20 

and  40  parts  to  the  inch 1.25         .14 

1634  Boxwood   White    Edge    Scale,    12-inch,    divided   30 

and  60  parts  to  the  inch :  .  .     1.25         .14 

1641     White  Edge  Offset  Scales,  2-inch,  divided  like  Nos. 

1632  and  1634,  each 70         .02 

FLAT    METALLIC    CHAIN-SCALES 

A   superior   article,   our   own   make,    made   of  brass,   and   nickel -plated. 
Divided  on  beveled  edges. 

1645  Flat  Metal  Scale,   12-inch,  divided  10  and  50  parts 

to  the  inch $3.00     $0.18 

1646  Flat  Metal  Scale,   12-inch,  divided  20  and  40  parts 

to  the  inch 3.00         .18 

1647  Flat  Metal  Scale,  12-inch,  divided  30  and  60  parts 

to  the  inch 3.76         .18 

1648  Flat  Metal  Scale,  12-inch,  divided  80  and  100  parts 

to  the  inch 5.00         .18 


1Z  11 


ENGINE  DIVIDED  ogW  U.S.  Sd 

0  Z         »         9         9         01        ZT        -H       9T        81     a       Oi        25       tS        35        BS       03 

w  /.#/.#  /.ft  /.ft  /.tf./. 


W.  &  L.  E.    GURLEY,    TROY,  N.    Y.  355 

No.  PRICE        POST. 

1649  Flat  Metal  Scale,  12-inch,  divided  100  and  500  parts 

to  the  foot $3.00    $0.18 

1650  Flat  Metal   Scale,  30  centimeters,  divided  to  milli- 

meters and  half-millimeters 3.75         .18 

TRIANGULAR   BOXWOOD    SCALES 


1656 

1655  Triangular  Boxwood  Scale,  6-inch,  divided  ^,  T*ff, 

£>  4>  |>  \y  t>  1»  H  and  3  inches  to  the  foot,  and 

one  edge  inches  and  I6ths $0.60     $0.04 

1656  Triangular  Boxwood  Scale,  12-inch,  divided  |,  \,  f, 

^,  |,  1,  1£,  2,  3  and  4  inches  to  the  foot,  and  one 

edge  inches  and  I6ths 1.00         .14 

1657  Triangular  Boxwood  Scale,  18-inch,  divided  £,  J,  f, 

},  f,  1,  1$,  2,  8  and  4  inches  to  the  foot,  and  one 

edge  inches  and  16ths 2.50 -       .20 

1658  Triangular  Boxwood  Scale,  24-inch,  divided  f ,  \,  f , 

£,  |,  1,  1£,  2,  3  and  4  inches  to  the  foot,  and  one 

edge  inches  and  16ths 4.25         .25 


1661 

1660  Triangular  Boxwood  Scale,  6-inch,  divided  10,  20, 

30,  40,  50  and  60  parts  to  the  inch 60         .04 

1661  Triangular  Boxwood  Scale,  12-inch,  divided  10,  20, 

30,  40,  50  and  60  parts  to  the  inch 1.00         .14 

1662  Triangular  Boxwood  Scale,  18-inch,  divided  10,  20, 

30,  40,  50  and  60  parts  to  the  inch 2.50         .20 

1663  Triangular  Boxwood  Scale,  24-inch,  divided  10,  20, 

30,  40,  50  and  60  parts  to  the  inch 4.25         .25 


356  W7-  <Sr>  Z.  ,£.   GURLEY,   TROY,  N.    K 

No.  .  PRICE  POST. 

1665  Triangular  Boxwood  Scale,  12-inch,  divided  20,  30, 

40,  50,  60  and  80  parts  to  the  inch $1.00  $0.14 

1668  Triangular  Offset  Scale,  2-inch,  divided  same  as 

No.  1660 60  .02 

1670  Triangular  Boxwood  Scale,  12-inch,  divided  100,  200, 

300,  400,  500  and  600  parts  to  the  foot 1.50         .14 


TRIANGULAR    BOXWOOD    SCALES    WITH    WHITE 

EDGES 

1674  White   Edge   Scale,    6-inch,    divided    same    as   No. 

1655 ...$1.50     $0.11 

1675  White   Edge   Scale,   12-inch,   divided   same   as  No. 

1656 2.50         .14 

1678  White    Edge    Scale,    6-inch,    divided   same   as   No. 

1660 1.50         .11 

1679  White    Edge    Scale,    12-inch,  divided   same   as   No. 

1660 2.50  .14 

1682  White  Edge  Scale,  12-inch,  divided  same  as  No. 

1665 2.50  .14 

1684  White  Edge  Scale,  12-inch,  divided  same  as  No. 

1670...  ,     2.50         .14 


METALLIC    TRIANGULAR    SCALES 


The  Metallic  Triangular  Scales  are  made  of  brass  tubing  with  the 
ends  closed,  nickeled  with  a  dull  finish,  and  weigh  about  three  and  one- 
half  ounces. 

The  liability  of  the  wood  scales  to  crack,  warp  or  twist,  the  chipping 
of  their  edges,  and  their  variation  from  standard  measurement,  are  well 
known  to  all  who  have  used  them.  These  objections  have  been  over- 
come in  the  metallic  scale. 

1690  Metallic  Triangular  Scale,  12-inch,  divided  same  as 

No.  1656 $2.50  $0.16 

1692  Metallic  Triangular  Scale,  12-inch,  divided  same  as 

No.  1660 2.50  .16 

1694  Metallic  Triangular  Scale,  12-inch,  divided  same  as 

No.  1665 2.50  .16 

1698     Guard  for  Triangular  Scale  (preventing  errors) 20         .02 


W.  6-  L.   E.    GURLRY,    TROY,  N.    Y.  357 

METRIC    SCALES   AND    RULES 

No.  PRICE        POST. 

1700  Flat    Boxwood    Scale,    20  centimeters,    divided    to 

millimeters  and  £  millimeters $0.60     $0.04 

1701  Flat    Boxwood    Scale,    30   centimeters,    divided    to 

millimeters  and  2  millimeters 75         .06 

1702  Flat    Boxwood    Scale,    50   centimeters,    divided    to 

millimeters  and  ^  millimeters 1.50         .18 

1703  Flat  White  Edge   Scale,   20  centimeters,  divided  to 

millimeters  and  £  millimeters 1.00         .12 

1704  Flat  White   Edge  Scale,   30  centimeters,  divided  to 

millimeters  and  i  millimeters 1.25         .14 

1706  Triangular  Boxwood  Scale,  20  centimeters,  divided 

.01,  .02,  .03, -.05,  .025,  .0125." 75         .12 

1707  Triangular   Boxwood  Scale,  30  centimeters,   divided 

to  .01,  .02,  .03,  .05,  .025^.0125 1.00  .14 

1710  Triangular  Boxwood  Scale,  30  centimeters,  divided 

to   millimeters    and  £    millimeters,  also   to   lOths, 

12ths  and  16ths  of  inches,  and  lOOths  of  a  foot.  ..  2.00  .14 
1712  Triangular  White  Edge  Scale,  30  centimeters, 

divided  same  as  No.  1706 2.50  .14 

1714  Triangular  White  Edge  Scale,  30  centimeters, 

divided  same  as  No.  1710 , 3.00  .14 

1718  Flexible  Wood  Rule,  four  feet,  eight  fold,  divided  to 

millimeters  and  16ths  of  inches,  spring-joints 50  .05 

171')  Flexible  Wood  Rule,  same  as  No.  1718,  and  with 

white  enamel  finish. .  .  .60         .06 


PAPER    SCALES 

1724  Paper  Scale,  l]-inch  wide,  12  inches  long,  gradua- 

tions on  one  edge  inches  and  lOths,  and  the  other 

feet  and  lOOths $0.10    $0.02 

1725  Paper  Scale,  same  as  No.  1724,  edges  20  and  40  parts 

to  the  inch 10         .02 

1726  Paper  Scale  same  as  No.  1724,  edges  16  and  48  parts 

to  the  inch 10         .02 

Paper  Scales,  printed  on  card-paper,  18  inches  long, 
for  architects  and  engineers,  as  follows  : 

1727  Series  A  contains  6  scales,  one  each  divided  to  \,  £, 

|,  1,  1£,  and  3  inches  to  the  foot,  each  scale 20         .04 

1728  Series  B  contains  6  scales,  one  each  divided  ^,  J, 

T3ff»  T5»»  !»  and  iHnch  to  the  foot,  each  scale  ."....        .20         .04 

1729  Series  C  contains  6  scales,  one  each  divided  to  10,  20, 

30,  40,  50  and  60  parts  to  the  inch,  each  scale 20         .04 


358  ^  &»  L.  E.   GURLEY,   TROY,  N,    K 

THACHER'S   CALCULATING    INSTRUMENT 

No.  PRICE        POST. 

1730  Thacher's  Calculating   Instrument,   with  cylinder  18 

inches  long.  Performs  a  great  variety  of  useful 
calculations  with  rapidity  and  accuracy.  In  ma- 
hogany box  and  with  instruction  book $35.00 

1731  Thacher's  Calculating  Instrument,  same  as  No.  1730, 

and  with  3-inch  reading  glass  sliding  on  brass  bar, 
adjustable  to  any  part  of  the  instrument  and  .for 
focus 45.00 

CIRCULAR   SLIDE-RULES 

1732  Crockett   Slide-Rule.     Applicable   to   any    width   of 

roadbed,  any  center  height,  any  length,  any  side 
slope  ratio,  and  to  sections  determined  by  any 
number  of  levels,  without  requiring  the  plotting  of 
the  end  sections.  16£  inches  diameter,  on  heavy 
cardboard $4.00  $0.35 

1734  Rudiger  Slide -Rule.      Applicable  to  use  with  center 

height,  and  the  surface  slope  measured  in  degrees. 

16^  inches  diameter,  on  heavy  cardboard 4.00         .:!•"> 

Descriptive  circular  of  the  Crockett  and  Rudiger  Slide  Rules  mailed 
on  application. 

BOXWOOD  AND  IVORY  POCKET  RULES,  ETC. 

1735  Boxwood  Rule,  one  foot,   four  fold,  8ths  and  IGths 

of  inches $0.10    $0.03 

1736  Boxwood  Rule,  one  foot,  four  fold,  edge-plates,  8ths 

and  16ths  of  inches 18         .03 

1737  Boxwood    Rule,    one   foot,    four   fold,    brass   edges, 

bound,  8ths  and  IGths  of  inches 30         .04 

1740  Boxwood  Rule,  two  feet,  four  fold,  8ths  and  Uiths 

of  inches 15         .05 

1741  Boxwood  Rule,  two  feet,  four  fold,  edge-plates,  8ths, 

lOths,  12ths  and  IGths  of  inches,  and  drafting- 
scales 25  .05 

1742  Boxwood    Rule,    two   feet,    four   fold,    brass    edges, 

bound,  8ths  lOths,  12ths  and  IGths  of  inches,  and 

drafting  scales 50         .06 

1743  Boxwood  Rule,  two  feet,  four  fold,  edge-plates,  8ths, 

lOths,    12ths   and    IGths   of   inches,    and   drafting 

scales,  and  inside  beveled  edges 50         .06 

1745     Boxwood   Caliper-Rule,    one   foot,    four   fold,   edge- 
plates,  8ths,  lOths,  12ths  and  IGths  of  inches. 40         .04 


W.  &  L.   E.   GURLEY,   TROY,  N.    Y.  359 

No.  PRICE        POST. 

1747  Ivory  Rule,  one  foot,   four  fold,   edge-plates,   8ths, 

lOths,  12ths  and  16ths  of  inches $1.40     $  .12 

1748  Ivory   Rule,   one  foot,   four  fold,  edge-plates,   8ths, 

lOths,   12ths  and  16ths  of  inches  and  lOOths  of  a 

foot , 1.85         .12 

1749  Ivory  Rule,  one  foot,  four  fold,  German  silver  edges, 

bound,  divided  like  No.  1747. 2.50         .13 

1750  Ivory  Caliper-Rule,  one  foot,  four  fold,  edge-plates, 

divided  like  No.  1748 2.15         .13 

1751  Ivory    Caliper-Rule,    one    foot,    four   fold,    German 

silver  edges,  bound,  divided  like  No.  1747 2.85         .13 

1753  Ivory    Rule,  two  feet,  four  fold,   edge-plates,   8ths, 

lOths,  12ths,  and  16ths  of  inches,  and  lOOths  of  a 

foot 4.25         .15 

1754  Ivory  Rule,  two  feet,  four  fold,  German  silver  edges, 

bound,  8ths,  lOths,  12ths,  and  I6ths  of  inches,  and 

drafting-scales ' 5.00  .15 

1755 A  Flexible  Wood  Rule,  four  feet,  eight  fold,  divided 

to  I6ths  of  an  inch  and  lOOths  of   a  foot,   with 

spring-joints 50  .05 

1755B  Flexible  Wood  Rule,  same  as  No.  1755 A,  and  with 

white  enamel  finish 75  .05 

1755C  Flexible  Wood  Rule,  six  feet,  twelve  fold,  divided 

same  as  No.  1 755A 75  .08 

1755D  Flexible  Wood  Rule,  same  as  No.  1755C,  and  with 

white  enamel  finish 90  .08 

1756 A  Flexible  Wood  Rule,  four  feet,  eight  fold,  divided 

to  I6ths  of  inches,  and  with  spring -joints 50  .05 

1756B  Flexible  Wood  Rule,  same  as  No.  1756A,  and  with 

white  enamel  finish 60         .05 

1757  Flexible  Wood  Rule,  four  feet,  eight  fold,  divided  to 

16ths  and  20ths  of  inches,  and  with  spring- joint. .        .50         .05 

1758  Boxwood  Shrink-Rule,  divided  to  8ths,  lOfhs,  12ths 

and  16ths  of  inches.       Either  24T%,  24£,  24|,  or 

•24  J= 24  inches.     Each  style 1.20         .18 

1760  Boxwood  Combination  Rule,  one  foot,  two  fold.  It 
combines  in  itself  a  Carpenter's  Rule,  Spirit-Level, 
Square,  Plumb,  Bevel,  Indicator,  Brace-Scale, 
Drafting- Scale  of  equal  parts,  T-Square,  Protractor, 
Right-angle  Triangle,  etc 2.00  .16 


360 


W.  6-  L.  E.   GUKLEY,   TROY,  N.    Y. 


1760 


1762 

For  prices,  see  pages  358,  359  and  361. 


1764 


W.  6-  Z.  E.   GURLEY,    TROY,  N.    Y.  361 

BOXWOOD   SLIDE-RULES.     SEE  PAGE  360 

No.  PRICE        POST. 

1761  Mannheim    Slide-Rule,    not     adjustable,     10-inch, 

divided   on    white    facings,    with    glass    indicator 

and  directions $3.00     $0.15 

1762  Faber's  Slide-Rule  and  Calculating  Scale,  10$-inch, 

with  glass  indicator  and  directions 3.75         .20 

1763  Students'    Slide-Rule,   for  beginners,   10-inch,  with 

indicator  and  directions   1.00         .15 

1764 A  Engineers'  Adjustable  Mannheim  Slide-Rule,  8-inch, 
divided  on  white  facings,  with  glass  indicator  and 
directions 4.60  .15 

1764B  Engineers' Adjustable  Mannheim  Slide-Rule,  10-inch, 
divided  on  white  facings,  with  glass  indicator  and 
directions. 4.50  .15 

1764C  Engineers'  Adjustable  Mannheim  Slide-Rule,  16- 
inch,  divided  on  white  facings,  with  glass  indicator 
and  directions  10.00  .30 

1765  Duplex  Slide-Rule,  10-inch,  divided  on  white  fac- 
ings, with  glass  indicator,  Arithmetical  slide  and 
directions 7.00  .15 

1767  Duplex  Slide-Rule,   10-inch,  divided  on  white  fac- 

ings, with  glass  indicator  and  both   Arithmetical 

and  Trigonometrical  slides  and  directions 8.50         .20 

1768  Stadia  Slide-Rule,  20-inch,  divided  on  white  facings. 

This  rule  is  designed  to  solve  the  equations  gen- 
erally used  in  stadia  measurements 12.50         .35 

1769  Engineers'    Adjustable    Mannheim    Slide-Rule,    20- 

inch,  divided  on  white  facings,  with  glass  indicator 

and  directions 12.50         .35 

For  Treatises  on  Slide-Rules,  see  pages  455  and  457. 


362 


W. 


L.  E.   GURLEY,    TROY,  N.    K 


STANDARD    STEEL   RULES 


No.                                    PRICE        POST.         No.                                    PRICE 
1770       3-inch      $0.35     $0.02      1775     18-inch  $2.00 

POST. 
$0.20 
.30 
.50 
dlows  : 

$0.22 
.55 

. 

$0.13 
.15 
)llows  : 

$0.  1  3 

1772       6-inch                   65          05      1776     24-inch               2  75 

1774     12-inch  1.25         .15      1777     36-inch  7.00 

These  rules  are  divided  on  four  edges  in  parts  of  inches  as  fc 
10,  20,  50,  100  ;  12,  24,  48  ;  16,  32,  64  ;  8. 

STANDARD   METRIC    STEEL    RULES 

1780     y^-meter           $0.45     $003       1783     £-meter             $200 

1781      |  -meter.              .85         .14       1784     1  -meter                8.00 

1782     TVmeter  1.25         .16 
These  rules  are  divided  to  millimeters  and  half-millimeters.  . 

TRIANGULAR   STEEL   RULES 

1785 

1785     3-inch  $0.50    $0.03       1787       6-inch  $1.00 
1786     4-inch                     70          05       1788     12-inch               2  00 

These  rules  are  divided  on  three  edges  in  parts  of  inches  as  fc 
20,  50,  100  ;  12,  24,  48  ;  16,  32,  64. 

SQUARE    STEEL    RULES 

^£)lj£^^ 

1790 
1790     :)-inch  $0.45     $0.03       1792     6-inch  $0.90 
1791     4-inch  ..               .60         .05 

These  rules  are  divided  on  four  edges  in  parts  of  inches  as  follows  : 
16,  32,  64,  100. 


STEEL    STRAIGHT-EDGES.     SQUARE  EDGES 

NICKEL- 
PLAIN     PLATED 

1800  15-inch.. $0.90  $1.15  ! 

1801  18-inch..   1.00     1.25 

1802  24-inch..   1.50     1.90 

1803  30-inch..   2.25     2.70 


NlCKEL- 

OST 

PLAIN    PLATED 

POST. 

.16 

1804 

36-inch  . 

$:; 

00 

S3 

50 

$0.40 

.18 

1805 

42-inch  . 

4 

00 

4 

50 

.50 

.24 

1806 

48-inch  . 

6 

00 

6 

60 

.65 

.30 

1807 

60-inch  . 

8 

00 

8 

70 

... 

W.  &  L.  E.   CUR  LEY,    TROY,  N. 


363 


STEEL   STRAIGHT-EDGES,    NICKEL   PLATED 
ONE  EDGE  BEVELED 


No.  PRICE  POST. 

1810  18-inch $2.00  $0.18 

1811  24-inch 3.00  .24 

1812  30-inch..  .        .    4.00  .30 


No. 

1813  36-inch 

1814  42-inch. 

1815  48-inch. 


PRICK  POST. 

.$5.00  $0.40 

.  6.50  .50 

.   8.00  .65 


MAHOGANY  STRAIGHT-EDGES;  AMBER-LINED 

ONE    EDGE   BEVELED 


1820 

1820 
1821 
1822 

18-inch.    . 
24-inch.    . 
30-inch.  .  . 

...$0.90 
.  ...   1.10 
.   1.25 

$0.06 
.16 
.18 

1823 
1824 
1825 

36  -inch. 
42-inch. 
48-inch. 

.$1.90 
.  2.50 
.  3.00 


$0.25 
.32 
.40 


MAHOGANY   STRAIGHT-EDGES,   EBONY-LINED 
SQUARE    EDGES 


1830  24-inch... 

1831  30-inch... 

1832  36-inch.  . 


1830 

$0.50     $0.08  [   1833  42-inch. 

60         .12      1834  48-inch 

80         .15      1835  60-inch 


...$1.00     $0.32 
...  1.35         .40 
.  2.00 


HARD    RUBBER    STRAIGHT-EDGES 
SQUARE  EDGES 


1840  18-inch. 

1841  24 -inch. 

1842  30-inch. 


1840 


$0.06 
.75        .08 
1.00         .18 


1843 
1844 
1845 


36-inch $1.35     $0.25 

42-inch 1.75         .32 

48-inch. .  .        .    2.25         .40 


364 


W.  <&•>  /,.  E.   GURLEY,    TROY,  A\    Y. 


HARDWOOD   STRAIGHT-EDGES 
ONE  EDGE  BEVELED 


1850 


No 

PRICB 

POST. 

No. 

PRICE 

1850 

18-inch  . 

$0.^0 

$0.06 

1854 

42-inch 

.  .$0.50 

1851 

24  -inch  . 

25 

.08 

1855 

48-inch 

.  .      .65 

1852 

30-inch 

30 

.12 

1  856 

60-inch  . 

1.00 

1853 

36-inch 

.40 

.15 

1857 

72-inch  .  . 

.    1.25 

POST. 


T-SQJJARES 


MAHOGANY  T-SQUARES  WITH   AMBER  EDGES 
AND   FIXED   HEAD 


1860 


1860  18-inch 

1861  24-inch 

1862  30-inch 


.$1.10  $0.25 
.  1.50  .35 
,  1.85  .45 


1863  36-inch 

1864  42-inch 

1865  48-inch 


$2.15  $0.50 
2.50  .55 
3.00 


MAHOGANY  T-SQUARES  WITH   AMBER  EDGES 
AND    SHIFTING    HEAD 


1870  18-inch.. 

1871  24-inch.. 

1872  30-inch  .  . 


$1.90    $0.30 

.   2.45         .40 

2.80         .50 


1873  36-inch 

1874  42-inch 

1875  48-inch 


$3.20 
3.60 
4.20 


J.55 
.60 


RUBBER   BLADE    T-SQUARES,    HARDWOOD 
HEAD,    FIXED 


1880  18-inch  .  . . 

1881  24-inch  .  . 


.$0.90 
,    1.25 


$0.25 
.35 


1882 
1883 


30-inch 
36-inch 


.$1.60 
2.00 


$0.45 
.60 


IV.  &  L.  £.   GURLEY,    TROY,  N.    Y. 


365 


RUBBER   BLADE   T-SQUARES,    HARDWOOD 
HEAD,    SHIFTING 

POST. 
$0.30 


No.  PRICE 

1888  18-inch $1.60 

1889  24-inch 2.00 


.40 


No. 
1890 


PRICE       POST 
30-inch $2.50    $0.50 


1891     36-inch. 


3.00 


STEEL   BLADE   T-SQUARES,  NICKEL-PLATED, 
WITH    FIXED   JAPANNED    IRON    HEAD 


1896 
1897 


18-inch 
24-inch . 


.$3.00 
..  3.50 


$0.35 
.40 


1898 
1899 


30-inch $4.50    $0.45 

36-inch.  .        ..   5.50         .50 


STEEL   BLADE   T-SQUARES,    NICKEL-PLATED, 
WITH    SHIFTING    JAPANNED   IRON  HEAD 


1902  18-inch ;$4.25 

1903  24-inch...        .   5.00 


$0.45 
.50 


1904 
1905 


30-inch $5.75     $0.55 

36-inch 6.75         .60 


HARDWOOD   T-SQUARES,  FIXED    HEAD 


1908  15-inch $0.30     $0.15 

1909  20-inch 40         .25 

1910  25-inch..  .45         .35 


1911  30-inch $0.50     $0.45 

1912  40-inch 75         .60 

1913  50-inch.  .          .1.00 


HARDWOOD   T-SQUARES,   SHIFTING    HEJAD 


1916  15-inch. 

1917  20-inch. 

1918  25-inch. 


.90 
.95 


).20 
.30 
.40 


1919  30-inch 

1920  40-inch. 

1921  50-inch 


.$1.00  $0.50 
.  1.25  .65 
.  1.60 


366  IV.  &>  L.  E.    GURLEY,    TROY,  N.    K 

No.  PRICE  POST. 

1924  Mahogany  T-Square,  80-inch  ebony-lined  blade  and 

fixed  head $1.20  $0.45 

1926  Mahogany  T-Square,  80-inch  ebony-lined  blade  and 

shifting  head 2.00         .50 

T-SQUARES  WITH    DEANE'S  PATENT  SWIVEL 
AND   ADJUSTMENT 


Shifting  Head  with  Adjustment 


1935.     STYLE  No.  3 


1930  24-inch,    Mahogany    Blade,    Amber    Edges,    Style 

No.  1 $3.65     $0.40 

1931  30-inch,    Mahogany    Blade,    Amber    Edges,     Style 

No.  1 4.15         .45 

1932  36-inch,    Mahogany    Blade,    Amber    Edges,     Style 

No.  1 4.75         .50 

1935  24-inch,    Mahogany    Blade,    Amber    Edges,     Style 

No.  3 3.15         .40 

1936  30-inch,    Mahogany    Blade,    Amber    Edges,    Style 

No.  3 3.65         .45 

1937  36-inch,    Mahogany    Blade,    Amber    Edges,.  Style 

No.  3...  4.25         .50 


W.  &>  L.  E.   GURLEY,    TROY,  N.    Y. 


367 


DRAWING-TABLES 


1954 


1956 


No.  PRICE 

1953  Drawing-Table,  ash  top,  24  x  22  inches $  8.00 

1954  Drawing-Table,  ash  top,  24  x  22  inches,  and  with  instrument 

shelf,  24  x  7  inches 9.00 

1950  Drawing-Table,  black  walnut  top,  20x22  inches,  instrument 
shelf,  20  x  7  inches,  two  instrument  drawers,  ornamented 

stand 12.00 

1958  Drawing-Table,  black  walnut  top,  20x22  inches,  with  instru- 
ment shelf  and  two  drawers,  and  with  folding  arm  and 
plain  shelf,  ornamented  stand 1 7.00 


These  Tables  are  adjustable  for  horizontal  and  angular  motion  and  for  heights 
about  30  to  44  inches.  The  shelves  and  drawers  remain  level  when  the  top  is  inclined. 
They  are  mounted  on  an  iron  stand  with  casters. 


368  IK  &  L-  F-   GURLEY,    TROY,  N.    Y. 

DRAWING-BOARDS   AND   TRESTLES 

No.  PRICE 

1960  Drawing- Board,  pinewood,  14  x  10  inches $0.35 

1962  Drawing- Board,  pinewood,  20x15  inches,  tongue  and 

groove  ends 75 

1964  Drawing- Board,  pinewood,  28x20  inches,  tongue  and 

groove  ends 1 . 50 

1966  Drawing-Board,     pinewood,    40x28     inches,    tongue     and 

groove  ends • 2.50 

1967  Drawing- Board,   pinewood,   55x33  inches,  dovetailed  cleats 

on  under  side 8.00 

1970     Drawing- Board,  with  mahogany  frame,  and  removable  pine- 
wood  center,  18  x  13  inches 3.00 

1972     Drawing- Board,  with  mahogany  frame,  and  removable  pine- 
wood  center,  25  x  17  inches 4.00 

Drawing-Boards  and  Trestles  of  any  size  made  to  order. 

1975     Pinewood    Horses,    37    inches    high,    35   inches   long,  with 

removable  sloping  ledges.     Per  pair 5.00 

1977  Folding  Trestle,  hardwood,  37  inches  high,  33  inches  long, 

26  inches  wide 8.00 

1978  Folding  Trestle,  hardwood,  37  inches  high,  combined  with 

adjustable    Drawing- Board   of  pinewood,    42  x  31    inches, 

and  hinged  to  the  Trestle.     All  folding  compactly 13.00 

1979  Folding  Trestle  and  Drawing- Board,  same  as  No.  1978,  but 

with  the  Drawing- Board  55  x  33  inches 16.00 


1978 


W.  &  L.  E.   GURLEY,   TROY,  N.    K 


369 


TRIANGLES 


OPEN   STEEL  TRIANGLES.     NICKEL-PLATED 

30°  x  60°  x  90° 


No. 


PRICE        POST. 


1982     G-inch  ........  $3.20    $0.15 


1984     8-inch. 


3.85 


No. 


PRICE        POST. 


198G     10^-inch $4.25     $0.25 

1989     15-inch C.50        .40 


45°  x  45°  x  90° 


1992    6f  inch. . . . . . .  3.50        .18 


1994     8-inch...          .  4.25 


.25 


1996     10-inch 5.50 

1998     12-inch...        .   6.50 


.35 
.45 


OPEN   GERMAN   SILVER  TRIANGLES 
30°  x  60°  x  90° 


2002     6-inch $2.50    $0.15 

2004    8-inch..         .    3.00        .20 


2006     10-inch $4.00    $0.26 


2008     12-inch 5.00 


45°  x  45°  x  90° 


2012     6-inch 2.75        .18 

2014     8-inch  . .          .   4.00         .25 


2016     10-inch 5.00 

2018     12-inch..          .   6.50 


.30 


.35 
.45 


TRANSPARENT   AMBER  TRIANGLES 


2022 

30°  x  60°  x90° 


2036 

45°  x  45°  x  90° 


For  prices,  see  page  370. 


370 


Z.  A.    CUR  LEY,   TROY,  A\    Y. 


TRANSPARENT   AMBER   TRIANGLES 
30°  x  60°  x  90° 


No.                                      PRICE  POST. 

2022  4-inch  . $0.25  $0.03 

2024  6-inch 40  .04 

2026  8-inch  .  .               .55  .06 


No.                                       PRICE  POST. 

2028  10-inch $0. 75  $0. 08 

2030  12-inch 1.00  .18 

2032  14-inch.  .          .   1.65  .20 


45°  x  45°  x  90° 

2036     4-inch 35         .04      2042 

2038     6-inch 55         .05      2044 

2040     7-inch 65         .07      2046 


8-inch 75         .08 

10-inch 1.10         .18 

12-inch 1.65         .20 


HARD    RUBBER   TRIANGLES 


2052 

30°  x  (10°  x  90°' 


2074 

45°  x  45°  x  90° 


30°  X  60°  X  90° 


2052  4-inch $0.20  $0.03 

2054  6-inch '    .30  .04 

2055  7-inch 35  .05 

2056  8-inch..               .45  .06 


2058 
2060 
2062 
2064 


10-inch. 
12-inch. 
14-inch. 
16-inch. 


.$0.65  $0.08 

.     .90  .10 

.   1.25  .20 

.   1.50  .25 


45°  x  45°  x  90° 


2074  4-inch 25  .04 

2075  5-inch 35  .05 

2076  6-inch 45  .05 

2077  7-inch 50  .07 


2078  8-inch. 

2080  10-inch. 

2082  12-inch. 

2084  14-inch. 


.65  .08 

.95  .10 

1.30  .20 

1.85  .25 


Other  sizes  of  Amber  or  Rubber  Triangles  to  order. 


W.  &>  L.  E.   GURLEY,   TROY,  N.    Y. 


371 


HARDWOOD   TRIANGLES,   OPEN   CENTER, 
FRAMED 


2092 

30°  x  60°  x  90° 


No.  PRICE        POST. 

2092       6-inch $0.20    $0.04 

2094       8-inch  .  .  .25         .06 


2096     10-inch 30 


.08 


No. 
2098 
2100 
2102 


2107  5-inch 

2108  6-inch 

2109  7-inch 


.20 
.25 
.30 


.05 
.05 

.08 


2110. 
2112 
2114 


30°  x  60°  x  90° 


45°  x  45°  x  90° 


2108V 

45°  x  45°  x  90° 

PRICE  POST. 

12-inch.. $0.40  $0.10 

14-inch 50  .12 

16-inch 60  .18 


8-inch .3$        .08 

10-inch 40         .10 

12-inch..  .50         .12 


HARDWOOD   TRIANGLES,  PLAIN 


45 


30°  x  60°  x  90° 


2120     4-inch $0.08     $0.03 

2122     6-inch..  .10         .04 


2124       8-inch $0.12     $0.06 

2126     10-inch..  .15         .08 


45°  x  45°  x  90° 


21 30  4-inch 

2131  5-inch  . . 


.04 
.05 


2132 
2134 


6-inch 15 

8-inch 18 


.05 
.08 


372  /*'.  &  L.  K.  cnu.EY,  TROY,  x.  v. 

HARD    RUBBER    LETTERING-TRIANGLES 


2140 


No.  PRICE        POST. 

2140     Lettering-Triangles  for  Block   Letters,  ;>£-inch,  three   . 

in  a  set.     Per  set $1.35     $0.12 


2145 


2145  Lettering-Triangles     for     Shaded     Letters,     o^-inch, 

three  in  a  set.      Per  set 1.20 

2146  Hard    Rubber    Lettering-Templets,    three   in    a   set. 

Per  set 1 .50 

2147  Transparent  Amber  Lettering-Templets,  three  in  a  set. 

Per  set .   2.00 


.12 
.15 
.15 


HARD    RUBBER   TRIANGLES   FOR    EMBANK- 
MENTS  AND   ROOF  PITCHES 

2160     Rubber  Triangles,  for  slopes  \  to  1 ,   \  to  1 ,  f  to  1 , 

1  to  1,  \\  to  1,  1£  to  1,  2  to  1,     Per  set  of  seven.  .$3.00     $0.16 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 
SECTION-LINERS 


373 


This  Section- Liner  is  positive  in  all  its  motions,  being  operated  by  a 
rack  and  pinion  movement.  The  rack-rod  passes  through  two  heavy 
weights  and  is  held  securely  by  clamp  screws.  Two  needle-pointed  pins 
aid  to  hold  the  weights  in  place  when  necessary.  -  Lines  can  be  drawn  at 
any  angle,  in  any  direction,  and  on  any  part  of  the  board. 


374 


IV.  &  L.  E.   GURLEY,   TROY,  N.    Y. 


SECTION-LINERS 

No.  PRICE 

2155  Section-Liner  with  12-inch  rack  and  12-inch  blade $6.50 

2156  Section-Liner  with  14-inch  rack  and  14-inch  blade 7.50 

Two  plain  notched  wheels  are  furnished  with  each  instrument  for 

producing  64  and  100  parts  to  the  inch.  Extra  wheels  for  either  10, 
12,  20,  24,  40,  48  or  60  parts  to  the  inch  will  be  furnished  for 
$1.50  each.  These  notched  wheels  when  graduated  on  the  face  for 
ruling  and  measuring  combined  will  cost  $2.25  each. 


2168 


No.  PRICE       POST. 

2168     Marion's    Section-Liner    with     7-inch     triangle    and 

10-inch  ruler $2.00    $0.20 

2170  Standard  Section- Liner.      Especially  adapted  for  school 

use  and  mechanical  sectional  drawing 1.75         .20 

2171  Casey's  Section-Liner  with  amber  triangle,  boxwood 

straight-edge  and  German  silver  mountings.  By  two 
scales  and  verniers  on  the  plates,  distances  are 
measured  to  y^th  inch  or  y^th  millimeter 3.50  .20 

2175  Terry's  Positive  Section- Liner  with  12-inch  rul5r  and 

brace  attachment 10.00 

2177  Both's  Section-Liner  and  Scale- Divider,  with  14f- 
inch  base,  9-inch  rack,  arm  10-inch  beyond  pro- 
tractor    12.00  .40 


IV.  &  L.  E.    GURLEY,    TROY,  N.    Y.  375 

IRREGULAR   CURVES   OF   HARD  RUBBER, 
AMBER   AND   WOOD 


2180,  2182   AND   2184 


376  ttr-  &  t<>  R.   GURLKY,   TROY,  N.    Y. 

IRREGULAR   CURVES   OF   HARD  RUBBER, 
AMBER   AND   WOOD 

See  patterns  on  page  375. 

No.                                                                                                                PRICK  POST. 
2180     Hard  Rubber  Curves,   Nos.   1,  2,  14,  16,  17,  22,  25 

and  26.     Each $0.35  $0.03 

Hard  Rubber  Curves,   Nos.    5,   15,   18,  21  and  28. 

Each 40  .03 

Hard  Rubber  Curves,  Nos.  3,  4,  13,  19,  20  and  24. 

Each 50  .05 

Hard  Rubber  Curve,  No.  27 75  .08 

Hard  Rubber  Curve,  No.  28 2.25  .18 

Hard  Rubber  Curve,  Logarithmic  Spiral,  No.  29 1.50  .18 

2182     Transparent  Amber  Curves,  Nos.  1,  2,  5,  16,  22,  25 

and  26.     Each 45  .03 

Transparent  Amber  Curves,    Nos.   3,  4,  13,  19  and 

20.      Each ..       .60  .05 

Transparent  Amber  Curve,  No.  24 .       .75  .05 

Transparent  Amber  Curve,  No.  27 90  .08 

2184     Wood  Curves,  Nos.  1,  5,  21,  25  and  26.     Each 20  .03 

Wood  Curves,  Nos.  3,  4,  13,  19,  20  and  24.     Each. .       .25  .05 

Wood  Curve,  No.  27 .35  .08 

ADJUSTABLE    CURVE-RULER 


2186 

2186  Adjustable  Curve-Ruler,  14^  inches  long $2.25     $0.15 

2187  Adjustable  Curve-Ruler,  30  inches  long 3.30         .35 

These  rulers  can    be  instantly  adjusted  and   retained  to 

any  form  of  curve. 

This  tool  is  recommended  by  architects  and  draftsmen, 
and  meets  a  long-felt  want.  It  is  well  made,  neatly  finished 
and  nickel-plated. 

ELLIPSES,   HYPERBOLAS   AND   PARABOLAS 

2190  Hard    Rubber    Ellipses,   6   in  a  set,   2   to   4J-inch. 

Per  set ." $1.50     $0.13 

2191  Hard   Rubber   Ellipses,    10  in  a  set,   \\  to  6-inch. 

Per  set 2.50  .16 

2194  Wood  Ellipses,  6  in  a  set,  2  to  \\  -inch.     Per  set 1.25  .13 

2195  Wood  Ellipses,  10  in  a  set,  \\  to" 6-inch.     Per  set. .  .  2.00  .16 
2200     Wood  Hyperbolas,  8  in  a  set,  2  to  5|-inch.      Per  set.  1.50  .15 
2204     Wood  Parabolas,  8  in  a  set,  \\  to  5J-inch.     Per  set.  .  1.50  .15 


W.  &>  L.  E.   G  UK  LEY,    TROY,  N.    Y. 


377 


RAILROAD   CURVES 


2210 

No.  PRICE        POST. 

Set  of  10  Curves,  cut  to  a  scale  of  inches,  from  12 
to  120  inches  radius,  varying  every  12  inches. 

2210  Rubber  Curves,  in  wood  box $6.00     $0.30 

2211  Wood  Curves,  in  wood  box 3.75         .30 

Set  of  24  Curves,  cut  to  a  scale  of  inches,  from  1£ 
to  24  inches  radius,  varying  every  \  inch  up  to  10 
inches  and  then  every  2  inches  up  to  24  inches. 

2214  Rubber  Curves,  in  wood  box 13.50         .40 

2215  Wood  Curves,  in  wood  box 8.00         .40 

Set  of  10  Curves,  cut  to  a  scale  of  40  feet  to  the 
inch,  from  1°  to  10°,  varying  every  degree. 

2218  Rubber  Curves,  in  wood  box 6.00         .30 

2219  Wood  Curves,  in  wood  box 3.75         .30 

Set  of  20  Curves,  cut  to  a  scale  of  40  feet  to  the 
inch,  from  1°  to  20°,  varying  every  degree. 

2222  Rubber  Curves,  in  wood  box 12.00         .35 

2223  Wood  Curves,  in  wood  box 7.50         .36 

Set  of  12  Curves,  cut  to  a  scale  of  100  feet  to  the 
inch,  from  1°  to  12°,  varying  every  degree. 

2226  Rubber  Curves,  in  wood  box 8.50         .30 

2227  Wood  Curves,  in  wood  box 5.50         .30 

Set  of  20  Curves,  cut  to  a  scale  of  400  feet  to  the 
inch,  from  30'  to  10°,  varying  every  30  minutes. 

2238  Rubber  Curves,  in  wood  box 12.00         .35 

2239  Wood  Curves,  in  wood  box 7.50        .35 


378 


W.  &  L.  E.   G UR LEY,   TROY,  N.    K 


PARALLEL  RULERS 


2250 

EBONY  PARALLEL  RULERS 


No. 
2250      6-inch  .  - 
2251       9-inch  .  . 
2252     12-inch 

J  RICH        POST. 
....  $0.30    $0.04 
50        .06 

75            08 

No.                                    PRICE        POST. 
2253     15-inch.            $1.00    $0.18 

2254     18-inch.  .  .           1.25         .20 

2255     24-inch  2.00         .24 

\RALLEL   RULERS 

2262     12-inch  $1.25     $0.16 
2263     15-inch  1.50         .18 

ULERS,    ON   ROLLERS 

2272     15-inch             $4.00    $0  30 

HARD   RUBBER   P, 

2260    6-inch  $0.75    $0.04 
2261     9-inch  1.00         .06 

EBONY    PARALLEL   R 

2270       9-inch  $2.75     $0.20 
2271     12-inch  3.25         .25 

HARD   RUBBER    PAE 
ROL 

2275       9-inch  $3.50    $0.20 
2276     12-inch.  .        .    4.25         .25 

2273     18-inch  5.00         .35 

.ALLEL   RULERS,  ON 
LERS 

2277     15-inch  $5.00    $0.30 
2278     18-inch               6.00         .35 

EBONY  PARALLEL  RULERS,  ON  ROLLERS 

WITH    WHITE   EDGES,    DIVIDED   £,    \,    \,    1    INCH   TO   THE   FOOT 


2280 


2280  12-inch $5.00    $0.25 

2281  15-inch 6.50        .30 


2282     18-inch $7.50    $0.35 


W.  6-  L.   E.   GURLEY,    TROY,  N.    K  379 

BRASS   PARALLEL    RULERS,  ON   ROLLERS 


No. 


PRICE        POST. 


2285       9-inch $7.25     $0.30 


2286     12-inch 8.50 


.40 


No. 


PRICE        POST. 


2287  15-inch $10.00    $0.50 

2288  18-inch...      .   12.00 


GERMAN    SILVER    PARALLEL    RULERS, 
ON    ROLLERS 


2202       9-inch...  ...  $8.50    $0.30 


2293     12-inch 10.00 


.40 


2294  15-inch $12.00    $0.50 

2295  18-inch...      .15.00 


PANTOGRAPHS   FOR   ENLARGING    OR 
REDUCING    DRAWINGS 


2300 

2300     Pantograph,   hardwood,  brass  mountings,   with  arms 

21  inches  long $1.75     $0.30 

2302     Pantograph,     hardwood,     nickel-plated    mountings, 

with  arms  18  to  20  inches  long. 2.50         .30 

2304     Pantograph,  hardwood,   brass  mountings,  with  arms 

22  inches  long 3.50 

2306     Pantograph,   hardwood,  brass   mountings,  with  arms 

41  inches  long 5.00 


380  ^  <Sr>  L.  £.   GURLEY,    TROY,  N.    K 


DRAWING-PAPER 


ARCHITECTS'   PAPER   FOR    PLANS 

WHITE,  STRONG,  SMOOTH    SURFACE 

No.  PRICE 

2350     Medium,  23  x  18-inch,  per  sheet,  6  cents  ;  per  quire..  $1.25 
2352     Super  Royal,   28  x  20-inch,  per  sheet,   8  cents;    per 

quire 1 . 75 

2355  30  inches  wide,  per  roll  of  10  yards 1.25 

2356  36  inches  wide,  per  roll  of  10  yards 1.50 

2367  42  inches  wide,  per  roll  of  10  yards 1.76 

WHATMAN'S    DRAWING-PAPER 

SELECTED,   BEST   QUALITY,  GRAINED   SURFACE 

2360  Demy,  20  x  15-inch,  per  sheet,  5  cents  ;   per  quire. .  .   $0.95 

2361  Medium,  22x1 7-inch,  per  sheet,  7  cents  ;    per  quire.     1.40 

2362  Royal,  24 x  19-inch,  per  sheet,  9  cents  ;  per  quire.  . .      1.80 

2363  Super  Royal,  27  x  19-inch,  per  sheet,  10  cents  ;    per 

quire 2.10         .53 

2365     Imperial,  30  x  22-inch,  per  sheet,  17  cents  ;  per  quire     3.00         .66 

2368  Double  Elephant,  40  x  26-inch,  per  sheet,  25  cents  ; 

per  quire 5.75       1.28 

WHATMAN'S    DRAWING-PAPER 

MOUNTED    ON    MUSLIN 

2370     Royal,  24  x  19-inch,  per  sheet $0.39     $0. 10 

2372     Imperial,  30  x  22-inch,  per  sheet .48         .13 

2374     Double  Elephant,  40  x  27-inch,  per  sheet 72         .18 

BRISTOL   BOARD   DRAWING-PAPER 

2380  Patent  Office  Bristol  Board,  15  x  10-inch,  per  sheet, 

6  cents  ;  per  dozen $0.60     $0.20 

2381  Bristol  Board,  20 x  15-inch,  per  sheet,  12  cents;  per 

dozen 1.20         .45 

2385     Patent  Office  Bristol  Board,  printed  with  border,  etc. , 

15  x  10-inch,  per  sheet,  10  cents  ;  per  dozen 85         .15 


W.  &  L.   E.    GURLEY,    TROY,  N.    Y.  381 

DETAIL  DRAWING-PAPER,  CREAM  BUFF  TINT 

SUPERIOR    QUALITY,    IN    ROLLS   OF   30   TO   40    POUNDS 

No.                                                                                                                     PRICE  POST. 

2389  30  inches  wide,  per  pound,  29  cents  ;  per  yard $0. 13  $0. 10 

2390  36  inches  wide,  per  pound,  29  cents  ;  per  yard 15  .12 

2391  42  inches  wide,  per  pound,  29  cents  ;  per  yard 20  .20 

BLEACHED   MANILLA   PAPER 

FOR    WORKSHOP    DRAWINGS,    BEST   AMERICAN    MAKE,   IN    ROLLS   OF   ABOUT 
50    POUNDS 

2395  36  inches  wide,  medium,  per  pound,  12  cents  ;    per 

yard $0.08     $0.12 

2396  42  inches  wide,  medium,  per  pound  12  cents  ;   per 

•      yard 10         .14 

2397  48  inches  wide,  medium,  per  pound,  12  cents;    per 

yard 12 

2398  54  inches  wide,  medium,  per  pound,  12  cents  ;   per 

yard 16 

AMERICAN    WHITE    ROLL    DRAWING-PAPER 

VERY    STRONG   AND   OF   EXCELLENT   QUALITY,    IN   ROLLS   OF 
ABOUT   40    POUNDS 

2410  36  inches  wide,  smooth  surface,  per  pound,  45  cents  ; 

per  yard $0.25     $0.12 

2411  42  inches  wide,  smooth  surface,  per  pound,  45  cents  ; 

per  yard 30         .14 

2413  62  inches  wide,  smooth  surface,  per  pound,  45  cents  ; 

per  yard 50 

2414  72  inches  wide,  smooth  surface,  per  pourjd,  50  cents  ; 

per  yard 75 

EXCELSIOR   WHITE    ROLL    DRAWING-PAPER 

IN    ROLLS   OF   ABOUT   40   POUNDS 

2420  36  inches  wide,  grained  surface,  per  pound,  40  cents  ; 

per  yard $0.20     $0.12 

2421  42  inches  wide,  grained  surface,  per  pound,  40  cents  ; 

per  yard 24-        .14 

Small  quantities  of  paper  must  be  put  on  a  wooden  roller  when  sent 
by  mail.  Several  .yards  can  be  put  on  a  single  roller,  with  but  little  extra 
for  postage.  The  pound  price  for  papers  Nos.  2389  to  2434  applies 
only  to  full  rolls. 


382  ^  &°  L.  E.   GURLEY,   TROY,  N.    K 

BEST   EGGSHELL   DRAWING-PAPER 

IN    ROLLS    OF   ABOUT   40   POUNDS 
No.  PRICE       POST. 

2430  36    inches   wide,    pebbled    surface,    per   pound,    60 

cents  ;  per  yard $0.33     $0. 13 

2431  42   inches   wide,    pebbled    surface,    per   pound,    60 

cents  ;  per  yard 38         .15 

2434  58   inches   wide,    pebbled    surface,    per   pound,    50 

cents  ;  per  yard 50 

2435  58  inches  wide,  thick,  pebbled  surface,  per  pound,  50 

cents  ;  per  yard ,65 


MOUNTED   DRAWING-PAPER 

WHITE,  MOUNTED   ON   MUSLIN,  IN   ROLLS   OF   10   YARDS 

2450  American,  36  inches  wide,  smooth  surface,  per  roll, 

$6.80  ;  per  yard $0.85     $0.25 

2451  American,  42  inches  wide,  smooth  surface,  per  roll, 

$8.20  ;  per  yard 1.00         .30 

2453  American,  62   inches  wide,  smooth  surface,  per  roll, 

$13.25  ;  per  yard 1.60 

2454  American,  72  inches  wide,  smooth  surface,  per  roll, 

$18.00  ;  per  yard 2.25 

2460  Eggshell,  36   inches  wide,  pebbled  surface,  per  roll, 

$7.50  ;  per  yard 1.00         .25 

2461  Eggshell,  42  inches  wide,  pebbled  surface,  per  roll, 

$8.85  ;  per  yard 1.10         .30 

2463  Eggshell,    58  inches  wide,   medium  thick,    pebbled 

surface,  per  roll,  $11.75  ;  per  yard 1.40 

2464  Eggshell,    58   inches   wide,   thick,    pebbled  surface, 

per  roll,  $12.60  ;  per  yard 1.50 

Large  pieces,  for  City,  County  or  State  Maps,  mounted  to  order. 
2467     Paper  Cloth,  38  inches  wide,  smooth  surface,  per  roll 

of  10  yards,  $4.00  ;  per  yard 45         .20 


DRAWING-PARCHMENT 

2468  38  inches  wide,  medium,  per  roll  of  20  yards,  $3.00  ; 

per  yard $0.20     $0.12 

2469  38  inches  wide,   thick,  per  roll  of  10  yards,  $3.20  ,- 

per  yard 45         .15 


m  &  L.  E.   GURLEY,   TROY,  N.    Y.  383 

TRACING-PAPER 

No.  PRICE        POST. 

2470  Pellucid,  common,  21  inches  wide,  per  yard,  5  cents  ; 

per  roll  of  20  yards $  0.75     $0.18 

2471  Pellucid,  common,  42  inches   wide,    per   yard,    10 

cents  ;  per  roll  of  20  yards 1.50         .40 

2472  Vegetable,  30  inches  wide,  per  yard,  10  cents  ;  per 

roll  of  20  yards 1.50  .40 

2474  Bank  Note,  36  inches  wide,  per  yard,  10  cents  ;  per 

roll  of  20  yards 1.62  .40 

2476  Parchment,  40  inches  wide,  per  yard,  25  cents  ;  per 

roll  of  20  yards 4.00         .60 

2478  Bond,  42  inches  wide,  per  yard,  15  cents  ;  per  roll 

of  20  yards 2.25         .45 

2479  Manilla,  common,  48  inches  wide,  per  yard,  7  cents  ; 

per  roll  of  20  yards 1.00         .50 

2480  Vegetable,  25  x  19  inches,  per  sheet,  10  cents  ;  per 

quire 2.00  .20 

2482  Flaxine,  31  x  21  inches,  per  sheet,  12  cents ;  per 

quire 2.50  .25 

2484  Bond,  21  x!6  inches,  per  sheet,  6  cents;  per  quire..  1.00  .20 

2486  Bond,  30x19  inches,  per  sheet,  8  cents;  per  quire..  1.40  .30 
2493  Pounce  Powder,  in  tin  shaker,  for  Tracing-paper  or 

Tracing-cloth,  each .15  .07 

IMPERIAL   TRACING-CLOTH 

IN    ROLLS   OF   24   YARDS,    FACE   GLAZED   AND    BACK    DULL 

2495  30  inches  wide,  per  yard,  40  cents  ;  per  roll $  8.10     $0.70 

2496  36  inches  wide,  per  yard,  45  cents  ;  per  roll 9.00       1.10 

2497  42  inches  wide,  per  yard,  60  cents  ;  per  roll 12.10       1.25 

2498  48  inches  wide,  per  yard,  80  cents  ;  per  roll 16.00 

2499  54  inches  wide,  per  yard,  85  cents  ;  per  roll 17.00 

PREPARED  BLUE-PRINT  PAPER 

BEST   QUALITY  ;     READY    FOR    IMMEDIATE    USE 

2506     Sensitized   Paper,    24   inches   wide,    per   yard,    15 

cents  ;  per  roll  of  10  yards $  1.20  $0.40 

2508  Sensitized  Paper,  30  inches  wide,  per  yard,  18 

cents  ;  per  roll  of  10  yards 1.50  .50 

2510  Sensitized  Paper,  36  inches  wide,  per  yard,  20 

cents  ;  per  roll  of  10  yards 1.65  .60 

2512  Sensitized  Paper,  42  inches  wide,  per  yard,  22 

cents  ;  per  roll  of  10  yards 1.80         .70 

2515  White  Ink,  for  altering  Blue-prints,  per  bottle 20         .06 

2516  Red  Ink,  for  altering  Blue-prints,  per  bottle 20         .06 


384 


W.  6-  L.  E.   GURLEY,    TROY,  N.    Y. 


BLUE-PRINT   PAPER,   NOT   PREPARED 

No  PRICE 

2520     24  inches  wide,  per  roll  of  10  yards $0.80 

2522     30  inches  wide,  per  roll  of  10  yards 1.00 

2524     36  inches  wide,  per  roll  of  10  yards 1.15 

2526     24  inches  wide,  per  roll  of  50  yards 3.20 

2528     30  inches  wide,  per  roll  of  50  yards 4.00 

2530     36  inches  wide,  per  roll  of  50  yards 4.75 

PRINT   FRAMES   AND   BATH   TRAYS 


POST. 

$0.35 

.45 

.55 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y.  385 

PRINT    FRAMES   AND   BATH    TRAYS 

No.  PRICE 
2534     Print  Frame,  complete  with  Plate  Glass  and  Cush- 
ion, 24  x  20  inches,  clear  exposure $  9.00 

2536     Print  Frame,  complete  with  Plate  Glass  and  Cush- 
ion, 30  x  24  inches,  clear  exposure 12.00 

2538     Print  Frame,  complete  with  Plate  Glass  and  Cush- 
ion, 42  x  30  inches,  clear  exposure 22.00 

2540     Zinc  Bath  Tray,  for  washing  copies,  24  x  20  inches. .  3. 75 

'2542     Zinc  Bath  Tray,  for  washing  copies,  30  x  24  inches. .  4.50 

2544     Zinc  Bath  Tray,  for  washing  copies,  42  x  30  inches. .  6.00 

Felt,  \  inch  thick,  for  Print  Frames,  per  square  foot,  .25 

THE   BLUE   PROCESS   OF   COPYING    TRACINGS 

Special  attention  is  directed  to  this  easy  process  of  copying  tracings, 
and  its  great  value  to  all  Engineers,  Architects  and  Mechanical  Draftsmen 
is  fully  recognized. 

If  not  convenient  to  procure  a  Print  Frame,  blue-prints  can  be  made 
readily  by  following  these  directions  : — 

1  Provide  a  flat  board  as  large  as  the  tracing  which  is  to  be  copied. 

2  Lay  on  this  board  a  cushion  of  blanket  or  felt  about  4 -inch  thick, 
to  give  a  slightly  yielding  backing  for  the  paper. 

3  Lay  on   the  blanket   the  prepared   paper  with  the  sensitive  side 
uppermost. 

4  Lay   on   this   paper   the   tracing,  making   it   as   smooth   as  possi- 
ble, so  as  to  insure  a  perfect  contact  with  the  paper. 

5  Lay  on  the  tracing  a  plate  of  clear  glass,  which  should  be  heavy 
enough  to  press  the  tracing  close  down  upon  the  paper.     Ordinary  plate- 
glass,  one  quarter  of  an  inch  in  thickness,  is  sufficient. 

6  Expose  the  whole  to  a  clear  sunlight  by  pushing  it  out  on  a  shelf 
from  a  window,  or  in  any  other  convenient  way,  from  four  to  six  minutes 
[in  winter,  six   to   ten   minutes].      If  a  -clear  sky  only  can   be  had,   the 
exposure  must  be  continued  from  twenty  to  thirty  minutes  ;  and  under  a 
cloudy  sky  from  sixty  to  ninety  minutes  may  be  needed,  the  shade  depend- 
ing on  the  time. 

7  Remove   the  prepared   paper  and  wash   it  freely  for  one  or  two 
minutes  in  clear  water,  and  hang  it  by  one  corner  to  dry. 

Too  light  a  blue  means  under-exposure,  and  too  dark  a  blue  is  over-exposuie. 


386  W.  &  L.  E.   G  UK  LEY,    TROY,  N.    Y. 

TIN   TUBES   WITH    SCREW   TOPS 

FOR    HOLDING    PREPARED    PAPER,  TRACINGS,  DRAWINGS,   ETC. 

No.  PRICE 

2546  Plain  Tin  Tube,  screw  top,  24  x  2£  inches $0.80 

2547  Plain  Tin  Tube,  screw  top,  30  x  1\  inches 95 

2548  Plain  Tin  Tube,  screw  top,  36  x  2|  inches 1.00 

2549  Plain  Tin  Tube,  screw  top,  42  x  2j  inches 1.10 

". 

TOWNSHIP   PLOTTING-PAPER 

• 

2550  Township    Plotting-paper,     Rulings    6x6    inches, 

blocks  1  inch  square,  per  quire $1.00     $0.10 

2552  Township    Plotting-paper,   Rulings    12  x  12  inches, 

blocks  2  inches  square,  per  quire 2.00         .25 

2553  Township   Plotting-paper,    Rulings  18x15  inches, 

per  quire 3.00         .30 

CROSS-SECTION   SKETCH    BLOCKS 

24   SHEETS 

2554  Sketch  Block,  7x5  inches,  24  sheets,  ruled  T^  of  an 

inch $0.75     $0.06 

2555  Sketch  Block,  10  x  7  inches,  24  sheets,  ruled  TL  of 

an  inch 1.25         .12 

2557  Sketch  Block,  18  x  13  cm.,  metric  ruling 75         .06* 

2558  Sketch  Block,  26  x  18  cm.,  metric  ruling 1.25         .12 

PLAIN    SKETCH    BLOCKS 

EACH    BLOCK    CONSISTS   OF   32    SHEETS   OF   BEST   QUALITY   WHATMAN'S 
DRAWING-PAPER 

2560  Sketch  Block,  7x5  inches,  unbound $0.50 

2561  Sketch  Block,  10  x  7  inches,  unbound 90 

2563  Sketch  Block,  14  x  10  inches,  unbound 1.60 

2565  Sketch  Block,  20  x  14  inches,  unbound 3.00 

2570  Sketch  Block,  7  x  5  inches,  bound 1.00 

2571  Sketch  Block,  10  x  7  inches,  bound 1.50 

2573  Sketch  Block,  14  x  10  inches,  bound 2.40 

2575  Sketch  Block,  20  x  14  inches,  bound 4.5P 

The  unbound  blocks  have  a  stiff  pasteboard  backing. 
The  bound  blocks  have  cloth  sides  and  leather  back,   with  a  portfolio 
and  loop  for  pencil  inside.     The  portfolio  will  last  for  a  number  of  blocks.  ; 


W.  &  L.  E.   GURLEY,   TROY,  N.    K 

PROFILE-PAPERS 


Sheets  :    Lines  printed  in  green. 
Continuous  :    Lines  printed  in  green  or  red. 
Continuous  on  tracing-paper  or  tracing-cloth  : 


Lines  printed  in  orange. 


No. 
2580 
2581 
2584 

2586 
2588 
2589 


PROFILE-PAPER,  PLATE  A 

PLATE  A.     Rulings  4  x  20  to  the  inch 

Plate  A,  sheet  42  x  15  inches,   per  quire 

Plate  A,  sheet  42  x  15  inches,  per  sheet 

Plate  A,  continuous,  20  inches  wide,  50  yards  in 
roll,  per  yard 

Plate  A,  continuous,  20  inches  wide,  mounted  on 
muslin,  20  yards  in  roll,  per  yard 

Plate  A,  continuous,  20  inches  wide,  on  tracing- 
paper,  50  yards  in  roll,  per  yard 

Plate  A,  continuous,  20  inches  wide,  on  tracing- 
cloth,  20  yards  in  roll,  per  yard 


PRICE 

$8.50 

.40 


POST. 

$0.75 

.05 


.24         .05 
.65         .08 


.24         .05 


.75 


.08 


PROFILE-PAPER,  PLATE  B.     See  page  388. 


388 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 


PROFILE-PAPERS 

PLATE  B.     Rulings  4  x  30  to  the  inch. 


No. 
2595     Plate  B,  sheet  42  x  13£  inches,  per  q 
2596     Plate  B,  sheet  42  x  13|  inches,  per  s 
2600     Plate  B,  continuous,  20  inches  wid 
roll,  oer  vard  

PRICK       POST. 
uirft     .  .                 $8  50     $0  75 

icet.  .                          40          05 

e,  50  yards  in 
.24         .05 

2602 
2604 
2605 

Plate  B,  continuous,   20  inches  wide,   mounted  on 
muslin,  20  yards  in  roll,  per  yard  .65         .08 

Plate   B,   continuous,   20   inches   wide,   on   tracing 
paper,  50  yards  in  roll,  per  yard                                       24          05 

Plate    B,   continuous,   20   inches   wide,   on   tracing 
cloth,  20  yards  in  roll,  per  yard   .                                     7"»          08 

:::::;::::;;:  ::i  I:;:;::::;;:;::::;:::::;:: 

iiiiiiiiiiiiiiLiiiiJiiiiiiiiniu 

PROFILE-PAPER,  METRIC 


2610  METRIC.  In  continuous  roll,  rulings  50  centimeters 
,  wide,  in  millimeters,  with  each  fifth  millimeter, 
each  centimeter,  and  each  decimeter  proportion- 
ally heavier  than  the  millimeters,  50  yards  in  roll, 
per  yard .24 

2612  Metric,  continuous,  mounted  on  muslin,  20  yards  in 

roll,  per  yard .60 


.05 
.08 


W.  &  L.   E.   GURLEY,    TROY,  N.    Y. 


389 


CROSS-SECTION    PAPERS 

Sheets  :     Lines  printed  in  green. 
Continuous  :     Lines  printed  in  green. 

'Continuous  on  tracing  paper  or  tracing  cloth  :     Lines  printed  in  orange. 
No.  PKICB        POST. 

2620     Cross-section  Paper,  Plate  C,  rulings  20x16  inches, 

8  feet  to  inch,  per  sheet,  20  cents  ;  per  quire $3.50    $0.40 


PLATE  F.  10  feet  to  one  inch. 

2621  Cross-section  Paper,  Plate  F,  rulings  20x16  inches, 

10  feet  to  inch,  per  sheet,  20  cents  ;  per  quire.. .  .        3.50         .40 

2622  Continuous  Cross-section  Paper,  Plate  F,  20  inches 

wide,  in  rolls  of  50  yards,  per  yard .24         .05 

2623A  Continuous  Cross-section  Paper,  Plate  F,  20  inches 
wide,  ruled  10  feet  to  inch  on  tracing-paper,  in 

rolls  of  50  yards,  per  yard .24         .05 

2623B  Continuous  Cross-section,  Plate  F,  20  inches  wide, 
ruled  10  feet  to  inch  on  tracing-cloth,  in  rolls  of 
20  yards,  per  yard 75  .08 


PLATE  G.    See  page  390. 


390 


W.  <5r=  Z.  E.    GURLEY,    TROY,  N.    Y. 


No. 


PRICE        POST. 


2624  Cross-section  Paper,  Plate  G,  rulings  20x16  inches, 

10  feet  to  inch,  every  fifth  line  heavy,  per  sheet, 

20  cents  ;  per  quire $3.50     $0.40. 

2625  Cross-section  Paper,  Plate  G,  printed  on  Parchment 

Tracing- Paper,    in    sheets,    20x16    inches,    per 

sheet,  20  cents  ;  per  quire 3.50         .25 

2626  Cross-section    Paper,    Plate     H,    rulings,    20x16 

inches,  16  feet  to  inch,  per  sheet,  20  cents ;  per 

quire 3.50         .40 

2627  Continuous  Cross-section  Paper,  Plate  H,  20  inches 

wide,  in  rolls  of  50  yards,  per  yard .24         .05 


MILLIMETER 


2630  Cross-section    Paper,    Metric,    rulings   every   milli- 

meter, size  of  sheet,  50  x  40  centimeters,  per  sheet, 

20  cents  ;  per  quire 3.50         .40 

2631  Continuous    Cross-section    Paper,    Metric,     rulings 

every  millimeter,  50  centimeters  wide,  in  rolls  of 

50  yards,  per  yard 24         .05 

The  following   Cross-section   Papers,  being   ruled,  are 
much  cheaper  than  those  printed  from  copper  plates  : 

2635  Ruled  Cross-section  Paper,  4  spaces  to  inch,  21  x  16 

inches,  per  quire 1.00         .35 

2636  Ruled  Cross-section  Paper,  8  spaces  to  inch,  21  x  16 

inches,  per  quire 1.00         .35 

2637  Ruled  Cross-section  Paper,  10  spaces  to  inch,  21  x  16 

inches,  per  quire 1.00         .35 

2638  Ruled  Cross-section  Paper,  12  spaces  to  inch,  21  x  16 

inches,  per  quire 1.00         .35 

2645     Crowell's  Adhesive  Tape,  f-inch  wide,  for  binding 

and  mending  drawings,  per  box  of  50  feet .25         .05 


2680  TO   2690  27O8 


No.  PRICE        POST. 

2680  Brass  Thumb  Tacks,  round  head,  J-inch  diam.,  per 

doz J $0.10    $0.02 

2681  Brass  Thumb  Tacks,  round  head,  f-inch  diam.,  per 

doz 15         .02 

2682  Brass  Thumb  Tacks,  round  head,  |-inch  diam.,  per 

doz 25         .02 

2684  German  Silver  Thumb  Tacks,  round  head,  f-inch 

diam. ,  per  doz .25      •   .02 

2685  German  Silver  Thumb  Tacks,  round  head,    J-inch 

diam.,  per  doz 30         .02 

2686  German  Silver  Thumb  Tacks,  round  head,   f-inch 

diam.,  per  doz .45         .03 

2689  German  Silver  Thumb  Tacks,  round  head,  superior, 

^-inch  diam.,  per  doz .70         .02 

2690  German  Silver  Thumb  Tacks,  round  head,  superior, 

f-inch  diam.,  per  doz .90         .03 

2692  Steel  Thumb  Tacks,   common,   f-inch  diam.,    per 

doz 08         .02 

2693  Steel  Thumb  Tacks,    common,   f-inch  diam.,    per 

box  of  100 55      "  .08 

2694  Steel  Thumb  Tacks,  common,  A-inch  diam.,    per 

doz 12         .02 

2695  Steel  Thumb  Tacks,  common,  T9g-inch  diam.,   per 

box  of  100 80  .10 

2697  Steel  Thumb  Tacks,  superior,  TVinch  diam.,  per 

doz. 80  .02 

2700  Thumb  Tack  Lifter  and  Paper-knife 20  .02 

2703  Brass  Paper  Fasteners,  prongs  j-inch,  per  doz .05  .02 

2705  Brass  Paper  Fasteners,  prongs  £-inch,  in  box,  per 

hundred 25         .08 

2707  Horn  Center,  plain 10         .01 

2708  Horn  Center  with  German  silver  rim .50         .01 

2710     Handy  Paper  Cutter,   brass   mounted,    for   cutting 

drawings  from  the  board .35         .03 


392  W-  &  L.  E.    GURLEY,    TROY,   N.    Y. 

CONTINUOUS   PROFILE-BOOKS 


2715 

These  books  are  for  field  or  office  purposes,  being  printed  on  a  tough 
thick  paper,  mounted  upon  a  continuous  piece  of  muslin  and  bound  in  book 
form  with  flexible  morocco  covers,  convenient  for  the  pocket.  Each  page 
will  contain  a  profile  of  three  thousand  feet  in  length,  so  that  each  folio 
will  contain  an  average  section  of  a  road  as  usually  laid  out  for  construction. 
Railroad  and  other  engineers  will  find  them  very  useful.  The  rulings  cor- 
respond to  our  large  profile-plates  A  and  B. 


No. 

2715 

Plate  A, 

2716 

Plate  A, 

2717 

Plate  A, 

2718 

Plate  A, 

2720 

Plate  B, 

2721 

Plate  B, 

2722 

Plate  B, 

2723 

Plate  B, 

about  8£  x  6  inches, 
about  8|  x  6  inches, 
about  8i  x  6  inches, 
about  84  x  6  inches, 
about  8x5^  inches, 
about  8x5}  inches, 
about  8  x  5}  inches, 
about  8x5^  inches, 


profile 
profile 
profile 
profile 
profile 
profile 
profile 
profile 


12  miles.  , 
25  miles.  . 
50  miles .  . 
100  miles. 
12  miles.  . 
25  miles.  . 
50  miles.  . 
100  miles. 


PRICE 
$2.00 
3.25 
5.25 
9.50 
2.00 
3.25 
5.25 
9.50 


POST. 
$0.15 
.18 
.20 
.28 
.13 
.15 
.18 
.25 


PLAT   AND   PROFILE-BOOKS 


These  books  are  9J  x  4}  inches,  oblong,  with  flexible  morocco  covers, 
containing  36  profile-pages,  plate  B,  and  the  opposite  pages  are  blank  for 
plats,  etc. 

2724A  Dunham's  Plat  and  Profile-book $1.00     $0.08 

2724B  Dunham's  Plat  and  Profile-book,  90  pages 2.00         .20 


W.  &  L.  E.   G  UK  LEY,    TROY,  N.    Y. 
ENGINEERS'  BLANK   FIELD-BOOKS 

LEATHER   BINDING  AND   ROUNDED  CORNERS 


393 


No.  PRICE       POST. 

2725     Level-books,  6f  x4J  inches,  60  leaves,  per  dozen, 

$5.00  ;  or  single $0.50    $0.05 


2728     Transit-books,  6|  x  4£  inches,  60  leaves,  per  dozen, 
$5.00  ;  or  single 


.50        .05 


2731     Record-books,  6f  x  4}  inches,  60  leaves,  per  dozen, 
$5.00  ;  or  single 


.50        .05 


394  W.  &  L.   E.   GURLEY,    TROY,  N.    Y. 

BLANK   FIELD-BOOKS 

No.  PRICE  POST. 

273.6  Cross-section  Books,  6f  x  4£  inches,  60  leaves,  ruled 

5  spaces  per  inch,  per  dozen,  $5.00  ;  or  single. .  .  $0.50  $0.05 
2738  Cross-section  Books,  6|  x  4%  inches,  60  leaves,  ruled 

10  spaces  per  inch,  per  dozen,  $5.00  ;  or  single.  .  .50  .05 
2740  Cross-section  Books,  8x7  inches,  80  leaves,  ruled 

5  spaces  per  inch,  per  dozen,  $10.00  ;  or  single.  .  1.00  .15 
2742  Cross-section  Books,  8x7  inches,  80  leaves,  ruled 

10  spaces  per  inch,  per  dozen,  $10.00  ;  or  single.       1.00         .15 


LYONS'   TABLES 

2746  Lyons'  Tables.  A  set  of  tables  for  finding  at  a  glance  the  true 
cubical  contents  of  Excavation  and  Embankment  for  the  follow- 
ing Bases,  and  Ground  and  Side  Slopes.  By  E.  M.  Lyons, 
C.  E. 

Sheet  No.     5.     Base  15  feet,  Slopes £  to  1 

Sheet  No.  17.     Base  25  feet,  Slopes H  to  1 

Sheet  No.  19.     Base  28  feet,  Slopes .  J  to  1 

Sheet  No.  21.     Base  30  feet,  Slopes l|-  to  1 

Sheet  No.  22.     Base  30  feet,  Slopes 1£  to  1 

Sheet  No.  23.     Base  32  feet,  Slopes 1    to  1 

Per  sheet 15  cents  ;  post.  5  cents. 

The  tables  are  printed  in  clear,  bold  type,  on  tinted  paper,  sheets 
25  x  16  inches.  They  may  be  used  by  candle-light  without  injuring  the 
eyesight.  Each  sheet  is  complete  in  itself,  and  embraces  all  that  is 
wanted  in  connection  with  Base  or  Slope  designated,  whether  on  level 
or  side-hill  cross-section. 

Tables  Nos.  1,  2,. 3,  4,  6,  7,  8,  9,  10,  11,  12,  13,  14,  15,  16,  18  and 
24,  quoted  in  our  previous  catalogues,  are  now  out  of  print. 


W.  &  Z.  E.   GURLEY,    TROY,  N.    Y.  395 

LEAD-PENCILS.     Black  Leads 

No.  PRICE       POST. 

2750     Faber's  Hexagon,  Siberian,  best  Drawing,  Nos.  2  B 

to  8  H,  per  dozen $1.25     $0.12 

2752     Faber's  Hexagon;  Drawing,  Nos.  1  to  5,  per  dozen.       .75         .04 

2754     Faber's  Round,  Drawing,  Nos.  1  to  4,  per  dozen.  . .       .60         .04 

2756     Faber's    Round,    No.    4,    small,    for    Drawing-Com- 
passes, per  dozen 60         .02 

2758     Faber's  Round,  Nos.   2  and  3,  with  rubber  tip,  for 

offices,  per  dozen 50         .04 

2765     Faber's   Artists'    Pencil,   with   movable  lead,    H  to 

6  H,  each 25         .02 

2768     Faber's  Siberian  Leads,  H  to  6  H,  for  Artists'  Pencil, 

6  in  box,  per  box .50         .04 

These  leads  fit  the  pencil  legs  of  modern  Draw- 
ing-Compasses. 

2770  Faber's  Siberian   Round   Pencils,  5  in  box,  2  B  to 

H,  per  box 50         .04 

2771  Faber's   Siberian   Round  Pencils,  7   in  box,  3  B  to 

2  H,  per  box 65         .05 

2772  Faber's   Siberian   Round  Pencils,  10  in  box,  4  B  to 

4  H,  per  box 90         .08 

2774     Faber's  Siberian  Round  Pencils,  5  in  box,  with  knife 

and  rubber,  per  box 75         .05 

2778     Hardtmuth's   Koh-i-noor  Pencils,   Hexagon,   Super- 
fine, H  to  8  H,  per  dozen 1.25         .12 

COLORED  PENCILS  AND  CRAYONS 

2785     Faber's  Round,  Red,  Blue,  Green  and  Yellow  Pen- 
cils, per  dozen $0.75     $0.05 

2790  Faber's    Round,    Wax   Crayon    Pencils,    6    in   box, 

assorted  colors,  per  box 75          .05 

2791  Faber's   Round,    Wax   Crayon   Pencils,    12  in  box, 

assorted  colors,  per  box 1.40         .15 


2795 

See  page  396. 


396  W.  &•  L.  E.   GURLEY,   TROY,  N.    Y. 

No.  PRICK        POST. 

2795  Venetian  Crayons,  dark  red,  for  marking  stakes,  per 

dozen $0.60    $0.15 

2796  Venetian  Crayons,  dark  blue,   for  marking   stakes, 

per  dozen '. .GO         .15 

2797  Hexagon  Lumber  Crayons,  red,  blue,  or  black,  per 

dozen .75         .15 

These  crayons  are  superior  quality  and  do  not  soil 
the  hands. 

STEEL   LETTERING   AND   WRITING-PENS 

2800  Gillott's  Mapping-pens,  per  dozen $0.60     $0.02 

2801  Gillott's  Lithographic  Pens,  per  dozen 60         .02 

2802  Gillott's  Crow  -Quill  Pens,  per  dozen 60         .02 

2806  Gillott's   Writing-pens,    No.    170,    per   dozen,     10 

cents ;  per  gross 1 .05         .10 

2807  Gillott's   Writing-pens,    No.    308,    per   dozen,     15 

cents  ;  per  gross ; 1 .40  .10 

2810  Falcon  Writing-pens,  No.  048,  per  dozen,  10  cents; 

per  gross .75  .04 

2812  Spencerian  Writing-pens,  per  dozen,  15  cents;  per 

gross 1.25  .10 

2814  Commercial  Writing-pens,  per  dozen,  10  cents  ;  per 

gross .75  .04 

2816  Penholders,  black  handle,  nickel  tip,  for  office  use, 

per  dozen 50        .05 

ROUND-WRITING    PENS,    FOR    OR.NAMENTAL 
LETTERING 


2820  2624 

2820     Pens,    single   pointed,    Nos.    1  to  6,  assorted,  per 

dozen $0.12  $0.02 

2822     Pens,  single  pointed,  Nos.  1  to  6,  assorted,  per  gross,       1.00  .15 
2824     Pens,  double  pointed,  Nos.  10,  20,  and  30,  assorted, 

per  dozen 35  .03 

2826     Sample  assortment  of  25  Pens,  per  box 35  .04 

2828     Penholders  for  round- writing  pens,  each .10  .02 

2830  Text-book  to  round-writing,  with  full  instructions  ..          .65  .05 

2831  Copy-book  for  round- writing  practice .35  .06 


W.   &  L.  E.    GURLEY,    TROY,  N.    K 


391 


STEEL    ERASING- KNIVES   AND 
PENCIL    SHARPENERS 

No.  PRICK 

2835     Steel  Blade  Eraser,  Cocoa  handle $0.35 

2830     Steel  Blade  Eraser,  Ivory  handle 50 

2838     Steel  Eraser,  long  knife  blade,  Cocoa  handle 50 

2839A  Metal  Erasing- Shield,  nickel-plated,  3f  x  2|  inches       .25 
2839B  Zylonite  Erasing-Shield,  4.}  x  2£  inches 25 


POST. 

$0.03 
.03 
.03 
.02 
.02 


2840 

2840  Faber's  New  Pencil  Sharpener  (superior). .  . . 

2842  Common  Pencil  Sharpener 

2843  Fine  Steel  Pencil -file,  with  sheath 

2844  Fine  Steel  Pencil-file,  with  Tack-lifter  at  end. 

ERASING    RUBBER 


.25 
.10 
.25 
.25 


.03 
.02 
.03 
.03 


2850  2862  2866 

2850     Faber's  Artists'  Rubber,  If  x  1    inch,  each $0.05  $0.01 

2852     Faber's  Artists'  Rubber,  If  x  1}  inches,  each 10  .02 

2854     Faber's  Artists'  Rubber,  2    x  If  inches,  each 15  .03 

2856     Faber's  Artists'  Rubber,  2}  x  H  inches,  each 25  .03 


398 


W.  <&*   L.  E.   GURLEY,    TROY,  N.    Y. 


No.  .                                                                                                                PRICE  POST. 

2858  Faber's  Kneaded  Rubber,  small $0.05  $0.01 

2859  Faber's  Kneaded  Rubber,  large 10  .02 

2861  Faber's  Circular  Ink-eraser 05  .01 

2862  Faber's  Ink-eraser,  1£  x  1  inch .05  .01 

2864     Faber's  Ink-eraser,  2f  x  1 J  inches 20  .03 

2866  Faber's    Combined    Ink    and    Pencil-eraser,    2^x1 

inch 15  .02 

2867  Faber's  Combined  Ink  and  Pencil -eraser,    2|xlf 

inches .25  .03 

2868  Faber's  Typewriters'  Rubber,  3£  x  $  inch 10  .02 


2870 


2870  Faber's  Pointed  Rubber,  2JxT\  inch, 

2871  Faber's  Pointed  Rubber,  3  x  f  inch .  . , 


.09 
.12 


.01 
.01 


2880 


2880  Bevel  Rubber,  green,  oblong,  No.  40 06  .01 

2882  Bevel  Rubber,  green,  oblong,  No.  20 12  .02 

2884  Bevel  Rubber,  green,  oblong,  No.  12 20  .03 

2887  Hardtmuth's  Pliable  Rubber,  grey,  flat,  No.  30 07  .02 

2888  Hardtmuth's  Pliable  Rubber,  grey,  flat,  No.  20 10  .03 

2889  Hardtmuth's  Pliable  Rubber,  grey,  flat,  No.  12 17  .04 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 


399 


2890 

No.                                                                                                                PRICE  POST. 

2890  Multiplex  Rubber,  superior  quality,  2  x  \  inch $0.10  $0.02 

2891  Multiplex  Rubber,  superior  quality,  2£  x  f  inch 16  .  .02 

2892  Multiplex  Rubber,  superior  quality,  2£  x  f  inch  ....          .26  .03 


2896 

2895  Sponge  Rubber,  for  cleaning  drawings,  2£xlf  x$ 

inch 30         .03 

2896  Sponge  Rubber,    for  cleaning  drawings,    2x2x1 

inch 30         .03 

2898     Sponge  Rubber,    for  cleaning  drawings,    4x2x1 

inch..  ...         .60         .06 


RUBBER    BANDS 

2900     Rubber  Bands,  No.  8,  |  x  ^  inch,  per  gross $0.16  $0.02 

2902     Rubber  Bands,  No.  29,  1£  x  \  inch,  per  gross 65  .05 

2904  Rubber  Bands,  No.  61,  2x  \  inch,  per  gross 1.00  .15 

2905  Rubber  Bands,  No.  63,  3  x  J  inch,  per  gross 1.50  .20 

2907     Rubber  Bands,  No.  200,  11  sizes  assorted,   1£  to  3 

inches,  per  box 1.00  .18 


THE 


400 


W,  &°  L.  E.    GURLEY,    TROY,  N.    K 


HIGGINS'    DRAWING-BOARD   AND    LIBRARY 
MUCILAGE 

No. 

2915  Drawing-board  Mucilage,  fine  quality,  3 -ounce  jar. . 

2910  Drawing-board  Mucilage,  fine  quality,  6-ounce  jar. .  . 

2917  Drawing-board  Mucilage,  fine  quality,  14-ounce  jar. . 

2918  Taurine  Mucilage,  fine  quality,  2-ounce  bottle,  with 

brush 

2919  Taurine  Mucilage,  fine  quality,  4-ounce  bottle,  with 

brush , .    

2920  Taurine   Mucilage,  fine  quality,  pint  bottle,  without 

brush  

2921  Taurine  Mucilage,  fine  quality,  quart  bottle,  without 

brush 

2923  Photo-mounter,  fine  quality,  3-ounce  jar 

2924  Photo-mounter,  fine  quality,  0-uunce  jar 25 


PRICE 

POST. 

$0.15 

$0.13 

.25 

.20 

.50 

.30 

.10 

.10 

.20 

.15 

.50 

.30 

.80 

.15 

.13 

.25 

.20 

2915 


2925 


IV.  &  L.  E.   GURLEY,    TROY,  N.    Y. 


401 


HIGGINS'  AMERICAN   LIQUID    DRAWING-INKS 

No.  PRICE 

2925  Waterproof  Black  Ink,  small  bottle $0.25 

2926  Waterproof  Black  Ink,  8-oz.  bottle 2.00 

2928  General  Black  Ink  (not  waterproof),  small  bottle 25 

2929  General  Black  Ink  (not  waterproof),  8-oz.  bottle 2.00 


No.  PRICE 

2930  Waterproof  Carmine  ..$0.25 

2931  Waterproof  Scarlet 25 

2932  Waterproof  Vermilion .      .25 

2933  Waterproof  Blue 25 

2934  Waterproof  Indigo 25 

2942  Waterproof  Ink,  any  of  the 

bottle .  . 


No. 
2935     Waterproof  Violet.. 
2936     Waterproof  Green  .  . 
2937     Waterproof  Yellow. 
2938     Waterproof  Brown  . 
2939     Waterproof  Orange. 

PRICE 
...$0.25 
...     .25 
...     .25 
..     .25 
...     .25 

above  colors,  per  large  (8-oz. 


2.00 


Postage  on  the  above  inks,  7  cents  each  small  bottle,  and  30  cents  each 
8-oz.  bottle. 


WINSOR   &    NEWTON'S   WATER-COLOR   LIQUIDS 

IN   GLASS    BOTTLES 


PRICE 

Silver  Ink $0.30 

Gold  Ink 30 

Indelible  Brown 30 

Front's  Brown 30 

Extract  of  Ox  Gall ..         .30 


Postage  on  the  above  inks,  7  cents  each  bottle. 


MISCELLANEOUS    LIQUID    DRAWING-INKS 


No. 
2945 
294G 
2947 

2948 

Indian  Ink,  Black. 
Chinese  White  
Carmine  
Sepia  

PRICE 
...$0.30 
30 
...     .30 
...     .30 

No. 
2950 
2951 
2962 
2953 

2949 

Prussian  Blue  .  . 

.30 

2954 

No.                                                                                                               PRICE  POST: 

2955  Devoe's  White  Ink,  per  bottle $0.25  $0.08 

2956  Bourgeois  Black  India  Ink,  per  bottle 25  .06 

2957  Photo-drawing  Ink,  Dead  Black,  per  bottle 20  .06 

2958  Box  of  Indelible  Drawing-inks,   six  bottles   (Blue, 

Brown,  Carmine,  Green,  Scarlet,  Yellow),  per  box     1.50  .35 
•_".  i.V.i     Winsor     &     Newton's    Waterproof     Drawing-inks 
(Black,    Brown,    Carmine,    Emerald  Green,    In- 
digo, Vermilion,  Yellow),  per  bottle 25  .06 


402  W.  &   L.  E.   GURLEY,    TROY,  N.    Y. 

CHINESE    INDIA    INK    FOR    GENERAL   DRAWING 


2968 

No.                                                                                                                PRICK  POST. 

2960     Oval,  Black,  Lion  Head,  3£  inches,  per  cake $0.35  $0.02 

2962  Round,  Black,  Lion  Head,  2£  inches,  per  cake 26  .02 

2963  Round,  Black,  Lion  Head,  4£  inches,  per  cake 65  .04 

2965     Hexagon,  Black,  Lion  Head,  3xf  inch,  per  cake. .          .50.  .03 

2967  Square,  Black,  Super  Super,  3x£  inch,  per  cake.. .          .50  .03 

2968  Square,  Black,  Super  Super,  3|x|  inch,  per  cake..        1.00  .12 

2970  Oblong,   Black,    Double  Dragon,   fine,  Sfxf  inch, 

per  cake 2.00  .12 

2971  Oblong,    Dead    Black,    for    Photo-drawing,    3£x£ 

inch,  per  cake 1.00  .12 

2972  Oblong,  Red  Ink,  fine,  2£  inches,  per  cake 75  .03 

2973  Oblong,  Blue  Ink,  fine,  2|  inches,  per  cake , .          .75  .03 

2974  Oblong,  Yellow  Ink,  fine,  2f  inches,  per  cake 75  .03 


JAPANESE    INDIA   INK 
For  drawings  in  which  the  ink-lines  are  washed  in  applying  colors 


2980 


No. 


2980  Oblong,  black,  fine  quality, 
2982  Oblong,  black,  fine  quality, 
2984  Oblong,  black,  fine  quality, 


PRICE  POST. 

inches,  small  cake.  .     $1.00  $0.12 

inches,  medium  cake       2.00  .13 

inches,  large  cake.  .        3.00  .14 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y.  4Q3 

WINSOR   &   NEWTON'S   WATER-COLORS 

MOIST   IN   CHINA   PANS,    OR   HARD   COLORS   IN   CAKES 
The  moist  colors  are  usually  preferred,  as  they  do  not  waste  by  crumbling 


WHOLE  CAKE 


HALF  CAKE 


WHOLE  PAN 


HALF  PAN 


No. 

2990 

Whole,  each,  25  cts. 

1 

Antwerp  Blue 

2 

Bistre 

3 

Blue  Black 

*  4 

British  Ink 

*  5 

Bronze 

6 

Brown  Ochre 

7 

Brown  Pink 

8 

Burnt  Sienna 

9 

Burnt  Umber 

94 
10 

Charcoal  Gray 
Chinese  White 

95 

Chrome  Lemon 

11 

Chrome  Yellow 

12 

Cologne  Earth 

*48 

Constant  White 

13 

Deep  Chrome 

;  Half,  each,  15  cts. 


Dragon's  Blood 
Emerald  Green 
Flake  White 
Gamboge 
u !,-_»_ 


Hooker's  Green  No.  1 
Hooker's  Green  No.  2 
Indian  Red 
Indigo 
Italian  Pink 
23     Ivory  Black 
*24     King's  Yellow 

25  Lamp  Black 

26  Light  Red 

27  Naples  Yellow 

28  Neutral  Tint 

29  New  Blue 


Olive  Green 
Orange  Chrome 
Payne's  Gray 
PrussiaruBlue 
Prussian  Green 
Raw  Sienna 
Raw  Umber 
Roman  Ochre 

38  Sap  Green 

39  Terre  Verte 

40  Vandyke  Brown 

41  Venetian  Red 

42  Vermilion 

43  Yellow  Lake 

44  Yellow  Ochre 


2992     Whole,  each,  45  cts. ;  Half,  each,  25  cts. 


*45 
46 
47 
49 
60 


Black  Lead 
Brown  Madder 
Cerulean  Blue 
Crimson  Lake 
Indian  Yellow 


Mars  Yellow 
Neutral  Orange 
Orange  Vermilion 
Purple  Lake 
Roman  Sepia 


Reuben's  Madder 
Scarlet  Lake 
Scarlet  Vermilion 
Sepia 
Warm  Sepia 


404 


W.  &•  L.  E.   GURLEY,    TROY,  N.    Y. 


No. 
2994 


Whole,  each,  65  cts.;  Half,  each,  35  cts. 


72  French  Blue 

75  Indian  Purple 

76  Intense  Blue 
61  Lemon  Yellow 

77  Mars  Orange 


67  Cadmium  Orange 

68  Cadmium  Yellow, 

Pale 

69  Cadmium  Yellow 
59    Cobalt  Blue 

97    Cobalt  Green 


2996     Whole,  each,  90  cts. ;  Half,  each  45  cts. 


65  Aureolin 

91  Aurora  Yellow 

66  Burnt  Carmine 
70  Carmine 


2998     Whole,  each  $1.40  ; 
83    Smalt 


i     71     Field's  Orange  Ver, 

"milion 

81     Madder  Carmine 
78     Pink  Madder 

[     92     Primrose  Aureolin 

Half,  each,  70  cts. 

84     Ultramarine  Ash 


Green  Oxide  of 

Chromium 
Permanent   Mauve 
Permanent  Violet 
Pure  Scarlet 
Violet  Carmine 


82  Purple  Madder 

80  Rose  Madder 

90  Scarlet  Madder 

93  Yellow  Carmine 


Colors  marked  *  are  not  made  in  pans. 
Postage  on  water  colors,  1  cent  each. 


The   following   colors   are   generally  used   by  Architects   and   Civil   and 
Mechanical  Engineers : 

Burnt  Umber  to  represent  earth. 

Burnt  Sienna  to  represent  wood. 

Light  Red  to  represent  brick. 

Sepia  and  Yellow  Ochre  to  represent  stone. 

Prussian  Blue  to  represent  wrought  iron. 

Payrte's  Gray  to  represent  cast  iron. 

Gamboge  to  represent  brass. 

Gamboge  and  Carmine  to  represent  copper. 

Prussian  Blue  and  Carmine  to  represent  steel. 

In  Topography  the  following  colors  are  generally  used : 

Hooker's  Green  No.  2  to  represent  grass. 

Burnt  Sienna  to  represent  cultivated  ground. 

Burnt  Sienna  and  Hooker's  Green  to  represent  uncultivated  ground. 

Indigo  and  Hooker's  Green  to  represent  swamp. 

Gamboge  and  Hooker's  Green  to  represent  trees. 

Yellow  Ochre  to  represent  roads  and  streets. 

Indigo  to  represent  water. 

Carmine  to  represent  buildings,  bridges  and  masonry. 

Sepia  to  represent  hills. 

Sepia  to  represent  shade  lines  and  shadows. 


W.  &  L.    E.   GURLEY,    TROY,  N.    Y. 


405 


3000 


3010 


WINSOR   &   NEWTON'S   WATER-COLORS 

IN    POLISHED    MAHOGANY    BOX,  WITH    LOCK    AND    KEY,   AND    DRAWER, 
PAINT-STONE,    WATER-GLASS,    INDIA   INK,    BRUSHES   AND   COLORS 


No. 
3000 
:;00'J 

3004 

3006 


PRICE 


Complete  Box,  with  12  colors,  whole  cakes  . . $  9.00 

Complete  Box,  with  18  colors,  whole  cakes 13.50 

Complete  Box,  with  12  colors,  half  cakes 6.00 

Complete  Box,  with  18  colors,  half  cakes 7,75 


POST. 

$1.00 

1.15 

.50 

.65 


EMPTY   JAPANNED   TIN   COLOR-BOXES 

3010  Japanned  Box,  to  hold  6  whole  or  12  half  pans. . .  .     $0.80  $0.06 

3011  Japanned  Box,  to  hold  10  whole  or  20  half  pans. .  .        1.00  .16 

3012  Japanned  Box,  to  hold  12  whole  or  24  half  pans. .  .        1.15  .20, 
3014     Japanned  Box,  to  hold  18  whole  or  36  half  pans. .  .        1.40  .26 


EMPTY  WOOD    SLIDE-LID    COLOR-BOXES- 

3015  Color-box  to  hold  6  whole  or  half  cakes $0.40     $0.04 

3016  Color-box  to  hold  12  whole  or  half  cakes 50         .08 

3017  Color-box  to  hold  18  whole  or  half  cakes.  .  .60         .12 


406 


&  L-  E-   GURLEY,   TROY,  N.    Y. 
WATER-COLOR   BRUSHES 


No. 
.'3020     Camel  Hair  in  Quills : 

No.  12345678 
Each,       $0.05     .05     .06     .06     .08     .08     .10     .10 

3025     Red  Sable  in  Quills : 

No.  12345678 
Each,       $0.10     .12     .15     .20     .25     .33     .45     .60 


«§ 


POST. 
$0.01 


POST. 

$0.01 


3030     Camel  Hair  in  Tin,  with  handle  : 


No.  1 
Each,       $0.10 


2 
.10 


4 
.12 


5 
.15 


.15 


POST. 

$0.02 


3035     Red  Sable,  in  Albata,  with  handle : 

No.  1      2       3       4        5        6       7       13         14  POST. 

Each,  $0.20  .25  .35  .45  .55  .65  .75  1.00  1.30  $0.02  to  $0.10 


3040 
3040     Camel  Hair  Sky  or  Wash  Brush,  in  Tin,  with  handle : 

No.  0  1  2  3  4 

Each,       $0,18  ,20  ,25  ,35  ,45 


POST. 
$0.02. 


W.  6-  L.  E.   GURLEY,   TROY,  N.    Y. 


407 


3045 

No. 
3045     Camel  Hair  Wash  Brushes  in  Tin,  with  two  points : 

No.  0  1  2  3  POST. 

Each,       $0.35  .40  .50  .65  $0.02 

WATER-GLASSES,  INK   AND   COLOR-SLABS 


3050 


3054 


PRICE        POST. 


Artists'  Water-glass,  2|  inches $0. 12 


Artists'  Water-glass,  2f  inches 

Artists'  Water-glass,  3|-  inches 

Ink  or  Color-slab,  2|  x  1^  inches 

Ink  or  Color-slab,  3J  x  2^  inches 

Ink  or  Color-slab,  4  x  2J  inches 

Ink  or  Color-slab,  4|  x  2f  inches 

Slate  Ink-slab,  3£  x  3£  inches,  with  glass  cover. .  .  . 
Glass  Ink-saucer,  with  cover,  3^  inches  .... 


.20 
.25 
.10 
.15 
.25 
.30 
.35 
.50 


.10 
10 
.05 
.07 
.10 
.15 
.15 
.15 


PATENT   INK-SLAB 


3070 

3070  Patent  Ink-slab,  China,  with  cover,  4J  x  If  inches.  .     $0.35     $0.12 

3071  Patent  Ink-slab,  China,  with  cover,  5£  x  2J-  inches. .          .40         .16 


408 


&  L.  E.   GURLEY,    TROY,  N.    Y. 
COLOR-SAUCERS 


No. 
3075 
3076 
3077 
3078 


3075 

Nest  of  5  Saucers  and  a  cover,  2f  inches,  per  nest.. 
Nest  of  5  Saucers  and  a  cover,  2|  inches,  per  nest.. 
Nest  of  5  Saucers  and  a  cover,  3^  inches,  per  nest.. 
Nest  of  5  Saucers  and  a  cover,  3f  inches,  per  nest.. 


PRICE 

$0.45 

.55 

.65 

.75 


POST. 
$0.10 

.20 

.28 
.35 


BRASS   STENCILS.     ALPHABETS  AND  FIGURES 

Height  of  Letters  

i^in.        y8'm.        %  in.        %  in.        %  in. 

3100     Stencil.  Alphabet  

$1.00    $1.15     $1.30    $1.50     $1.75 

3101     Stencil  Alphabet  

1.85       2.00       2.15       2.30       2.50 

3102     Stencil  Alphabet...  . 

4.00       4.15       4.30       4.50       4.75 

3103     Stencil  Alphabet  

1.85       2.00       2.15       2.30       2.50 

•    lin. 

$2.00 
2.75 
5.00 
2.75 

A  set  of  Figures  to  match  any  of  these  Alphabets  will  cost  one-third 
the  price  of  the  same  style  and  size  of  Alphabet. 

Postage  on  each  Alphabet $0.14 

Postage  on  each  set  of  Figures,  Nos.  3100,  3101,  and  3103,         .04 
Postage  on  each  set  of  Figures,  No.  3102 .12 


BRASS    STENCIL    PLATES 


3110 
3111 
3112 
3115 
3116 
3120 
3121 


PRICE 

North  Point,  full  size i $0.50 

75 

60 

1.00 

75 

25 

.26 


North  Point,  full  size 

North  Point,  full  size 

Ornamental  Corner,  full  size .... 
Ornamental  Corner,  full  size.  .  .  . 

Dasher,  full  size 

Dasher,  full  size 


POST. 
$0.02 
.02 
.02 
.10 
.03 
.02 
.02 


A  Stencil  Brush  is  furnished  without  extra  charge. 
Use  thick  India  ink  for  marking. 

Other  styles  and  sizes  of  Alphabets,  Figures,   and  Stencil  Plates  made 
to  order. 


W.  <Sr»  L.  E.   GURLEY,  TROY,  N.    K  409 

STENCIL   PLATES 


EMIKA43 

3100  3101  3102  3103 


— ^^^^^  ^F    — 

31  10 

V* 


• 


y 
—I' 


31  12 


3120 


3121 

For  prices,  see  page  408. 


410  W.  &  L.  E.   GURLEY,   TROY,  N.    K 

COMMON   POCKET   COMPASSES 


3154 


3160 


No. 
3150 
3152 
3154 


3155 
3160 
3161 
3164 
3165 
3166 
3168 


PRICE        POST. 

Wood  case,  stop  to  needle,  2  inches  square,  French.  $2.00  $0.12 
Wood  case,  stop  to  needle,  3  inches  square,  French.  2.50  .15 
Government  pattern,  mahogany  case,  3  inches 

square,   raised  ring,  0°  to  360°,  superior  2-inch 

needle  with  stop,  Gurley,  maker 4.00         .15 

Compass,  like  No.  3154,  but  with  raised  ring  0°  to 

90°  each  way,  3f  inches  square  and  2^-inch  needle       5.00         .20 
Brass,  round,  watch  pattern,  stop,  agate  center,  \\ 

inches  diameter. 

Brass,  round,  watch  pattern,  stop,   agate  center,  2 

inches  diameter 

Brass,  round,  stop,  agate  center,  1J  inches  diameter, 

with  cover 

Brass,  round,  stop,  agate  center,  2  inches  diameter, 

with  cover 

Brass,  round,  stop,  agate  center,  1\  inches  diameter, 

with  cover  (superior) 2.50 

Brass,  round,  watch  pattern,  stop,  agate  center,  1^ 

inches  diameter,  with  hinged  cover 1.25 


.85  .04 
1.00  .12 
1.10  .12 


1.25 


.12 


.14 
.12 


W.  &  L.  E.   GURLEY,    TROY,  N. -Y. 


411 


No.  PRICE        POST. 

3170     Brass,   round,  watch  pattern,  stop,  agate  center,   2 

inches  diameter,  with  hinged  cover $1.50      $0.12 


3175 

3175  Pocket  Compass,  If  inches  diameter,  hunting-case, 

spring  catch,  stop  to  needle  in  joint  of  cover,  and 

bar  needle  with  agate  center 3.50          .12 

3176  Pocket  Compass,  2^  inches  diameter,  hunting-case, 
«          spring  catch,  stop  to  needle  in  joint  of  cover,  and 

bar  needle  with  agate  center 4.50          .12 


3182 


412 


W.  &>  Z.  £.   GURLEY,   TROY,  N.    Y. 


'  No.  PRICE        POST. 

3182  Pocket   Compass,  2£  inches    diameter,   with  cover, 

folding  sights,  bar  needle  with  agate  center,  and 

stop  to  needle $5.50       $0. 14 

3183  Pocket   Compass,   3    inches    diameter,   with   cover, 

folding  sights,  bar  needle  with  agate  center,  and 

stop  to  needle 6.50  .16 


3186        As  Clinometer 


3186  Clinometer  Compass,  2£  inches  diameter,  graduated 

to  one  degree,  bar  needle  with  agate  center  and 
stop,  pivoted  sights  to  swing  over  compass  face, 
cover,  and  morocco  case 7.25  .15 

3187  Clinometer  Compass,  3  inches  diameter,  graduated 

to  one  degree,  bar  needle  with  agate  center  and 

stop,  pivoted  sights,  cover,  and  morocco  case.  ...       8.75         .18 

3188  Pocket   Compass,   3f  inches  diameter,  heavy  brass 

case  and  cover,  2^-inch  needle  with  agate  center 

and  stop,  superior,  Gurley,  maker - 6.00  .20 

3192  Pocket  Compass,  If  inches  diameter,  watch  pattern, 

stem  stop,  Singer's  patent  pearl  dial 3.85  .12 

3194  Geological  Compass,  2|  inches  diameter,  with  pen- 
dulum, for  ascertaining  the  angle  of  dip  in  rocks..  4.25  .15 

3200  Pocket  Compass,  watch  pattern,  2£  inches  diameter, 
hunting-case,  raised  ring,  agate  center,  stop  to 
needle,  folding  sights 5.00  .15 


W.  &  L.  E.    GURLEY,    TROY,   N.    K  413 

PRICE        POST. 

Brunton  Pocket  Transit.  Designed  for  civil  and 
mining  engineers,  mine  managers  and  geologists. 
'  Can  be  used  as  a  prismatic  compass,  sighting  com- 
pass, clinometer  and  Abney  Level.  Aluminum 
case.  Size  2f  x  2|  x  1  inch.  Weight  8  ounces .  . .  $25.00  $0.25 

Pocket  Alt-Azimuth,  with  Telescope,  for  travelers 
and  military  surveyors.  Altitudes,  azimuths,  com- 
pass bearings,  clinometer  degrees  and  levels  are 
all  obtained  by  this  instrument.  Size  63  x  2£  x  1  \ 
inches,  in  case 50.00  .40 

PRISMATIC   COMPASSES 


3225 

• 

Prismatic  Compass,  1\  inches  diameter,  hunting- 
case  ;  can  be  used  as  an  ordinary  compass  without 
opening  the  cover,  and  a  prismatic  compass  by 
raising  the  cover,  glazed  with  a  stout  glass,  on 
which  is  etched  a  line  for  the  sight.  With  folding 

prism  and  floating  card  dial  with  stop $15.00     $0.15 

Prismatic  Compass,  of  inches  diameter,  with  float- 
ing metal  dial,  azimuth  glasses,  folding  prism, 
folding  sight  with  hinged  mirror,  ball-joint  and 
staff  socket,  in  morocco  case 7 21.50  .25 


414  W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 

PRISMATIC   COMPASSES 

No.  PKICE        POST. 

3227  Prismatic  Compass,  3  inches  diameter,  with  floating 
card  dial  graduated  to  £  degrees,  folding  prism 
and  folding  sight  (nearly  enclosed  top),  in  leather 

sling  case $16.00     $0.20 

. 


3228 


3228  Prismatic  Compass,  3  inches  diameter,  with  floating 
metal  dial  divided  to  £  degrees,  agate  center  with 
stop,  folding  prism,  and  folding  sight  (nearly 
enclosed  top  not  shown  in  cut),  in  leather  sling 
case , 20.00  .20 

3230  Prismatic  Compass,  Barker's  Patent,  2f -inch' floating 
dial,  agate  center  with  stop,  mounted  beneath 
2|-inch  pendulum  dial,  graduated  for  altitudes  0° 
to  180°,  also  graduated  0°  to  90°  both  ways  as 
clinometer  and  with  scale  of  rise  or  fall  in  inches 
per  yard ;  folding  prism  and  hair  sight,  metal 
case,  and  in  leather  sling  case 27.00  .25 

3232  Prismatic  Compass,  3  inches  diameter,  with  metal 
dial  graduated  to  £  degrees,  agate  center  with 
stop,  folding  prism,  azimuth  glasses,  folding  sight 
with  hinged  and  sliding  mirror,  metal  cover,  in 
leather  sling  case 30.00 


W.  &>  L.  E.   GURLEY,   TROY,  N.    Y. 


415 


SEXTANTS 


PRICE 


Pocket  Sextant,  graduated  to  \  degrees,  with  vernier 
to  1  minute,  telescope,  two  neutral  glasses,  mag- 
nifier, tangent  screw,  etc.  In  metal  box  3  inches 
diameter,  and  in  leather  sling  case $42.50 

Sextant  of  gun-metal,  4£  inches  radius,  arc  of  150° 
graduated  on  silver  to  15  minutes  with  vernier  to 
15  seconds,  clamp  and  tangent  and  magnifier, 
one  terrestrial  telescope,  one  celestial  telescope, 
one  sight-tube,  six  neutral  glasses,  two  mirrors, 
in  mahogany  box 50.00 

Sextant  of  gun-metal,  6^  inches  radius,  arc  of  150° 
graduated  on  silver  to  10  minutes  with  vernier  to 
10  seconds,  clamp  and  tangent  and  magnifier, 
two  celestial  telescopes,  one  terrestrial  telescope, 
one  sight-tube,  seven  neutral  glasses,  two  mirrors, 
in  mahogany  box 80.00 


3248 


Sextant  of  gun-metal,  superior,  7  inches  radius,  arc 
of  150°  graduated  on  silver  to  10  minutes  with 
vernier  to  10  seconds,  clamp  and  tangent  and 
magnifier,  two  celestial  telescopes,  one  terrestrial 
telescope,  one  sight-tube,  seven  neutral  glasses, 
two  mirrors,  in  mahogany  box 100.00 


416  W.  &°  L.  E.   GURLEY,    TROY,  N.    K 

ARTIFICIAL   HORIZONS,  ANGLE-MIRRORS   AND 
PRISMS.     SURVEYORS'  CROSS-STAFF   HEADS 

No.  PRICE  POS 

3250  Artificial  Horizon,  with  black  glass  plane  mounted 

in   brass  frame,   with  three   leveling-screws,  and 

sensitive  level-vial.  All  in  mahogany  box $16.00  $0.3 

3252  Mercurial  Horizon,  iron  trough,  iron  bottle  with 

screw  stopper  and  funnel  cap,  glazed  metal  roof. 

All  in  mahogany  box   .  . 30.00 


3265 

3255  Angle-mirror,  with  small  plummet,  for  angles  of  90°. 

The  handle  can  be  detached  and  stored  in 
frame  of  instrument.  Size,  2£  x  2  x  If  inches,  in 
morocco  case 7. 50 

3256  Angle-mirror,   plain,  for  angles  of  90°,  in  morocco 

case 5.00 

3260  Rectangular  Prism,  for  angles  of  90°,  2|xl|  xlf 

inches,  in  morocco  case 5.00 

3262  Double  Prism,  to  take  angles  of  90°  and  45°,  in 

morocco  case 10.00 

3264  Penta-prism  Range  Finder,  brass  mounted,  in  leather 

case,  with  directions.     Distances  up  to  two  miles 

easily  determined 10.00 

3265  Surveyors'  Cross-staff  Head,  for  45°  and  90°  angles. 

Octagonal,  2£  inches  long.     With  staff  socket. ...       2.75 

3266  Surveyors'  Cross-staff  Head,  for  45°  and  90°  angles. 

Octagonal,  3  inches  long.  With  magnetic  com- 
pass, If -inch  needle,  and  with  staff  socket 4.75 

3267  Surveyors'  Cross-staff  Head,  for  45°  and  90°  angles. 

Round,  3|  inches  long.  With  vertical  axis  gradu- 
ated to  1°  and  vernier  to  3  minutes.  With  mag- 
netic compass,  2^-inch  needle,  and  with  staff 
socket..  11.50 


IV.  6-  Z.  E.   GURLEY,    TROY,  N.    K 


PEDOMETERS, /PASSOMETERS,  TALLY 
REGISTER   AND   ODOMETER 


3270 


3276 


327*2 
3276 


PRICK  POST. 
Pedometer,  watch  form.  One  dial  registers  distance 

walked  up  to  12  miles  by  each  \  mile $4.50  $0.12 

Pedometer,  watch  form.  Two  dials  register  distance 

walked  up  to  50  miles  by  each  80  yards 5.25  .12 

Passometer,  watch  form.  Three  dials  register  each 

step  up  to  25,000  steps,  and  with  stem  attachment 

to  set  the  pointers  to  zero  at  will 6.00  .12 

Passometer,  like  No.  3276,  "but  with  four  dials, 

registering  each  step  up  to  100,000  steps 6.50         .12 


See  page  418. 


3282 


418 


VV. 


L.  E.   GURLEY,    TROY,  N.    Y. 


No.  PRICE       POST. 

3280  Tally  Register,  for  surveyors  and  others ;    useful  in 

chaining,  for  counting  persons,  cattle,  coal,  wheat, 

etc.   Registers  to  999  and  can  be  set  to  zero  at  will .  .     $2. 50     $0. 15 

3281  Tally  Register,   similar  to  No.  3280,  with  4  dials. 

Registers  to  10,000,  and  can  be  set  to  zero  at  will .  .        5.50         .20 

3282  Veeder  Odometer,  with  fixtures  for  attaching 3.50         .20 

This  Odometer  registers  on  the  dial  every  fifth  revo- 
lution of  the  carriage  wheel. 


3288 

See  page  419. 


W.  &   Z.  E.   GURLEY,   TROY,  N.    Y. 


419 


CLINOMETERS 

SEE  CUTS,  PAGE  418 
No.  PRICB       POST. 

3284     Clinometer  or  Slope-level,  Gurley,  maker,  7  inches 

long,  arc  to  whole  degrees,  in  wood  case $8.00     $0.30 

3288  Clinometer  or  Slope-level,  Gurley,  maker,  6  inches 
long,  arc  to  whole  degrees,  two  levels,  sights  and 
staff  mountings,  in  wood  case 16.00  .50 

3290  Boxwood  Clinometer,  12-inch,  folding  to  6-inch, 
with  two  levels,  compass,  inclination  scale,  and 

sights,  in  leather  case 12.00         .20 

The  inclination  scale  gives  the  value  of  any 
angle.  The  angle,  ascertained  from  the  graduated 
arc,  refers  to  that  degree  in  the  column  marked 
"angle,"  and  another  column  gives  the  rise  or  fall 
in  any  given  distance. 


3290 


3292 


Clinometer  or  Slope-level,  brass  frame,  4  inches 
square,  arc  to  whole  degrees  and  vernier  to  5 
minutes.  The  design  renders  the  measurement 
of  the  inclination  of  the  under  side  of  a  plane 
available,  as  any  of  the  four  edges  may  be  used  ; 
in  case.  .  .  . .. 10.00 


.40 


420  *K  &  L.  E.   GURLEY,   TROY,  N.    Y. 

ANEROID   BAROMETERS 

FOR    ASCERTAINING    HEIGHTS,    DIFFERENCES   OF    LEVEL   AND    METEORO- 
LOGICAL  CHANGES,    APPROACH    OF   STORMS,    ETC. 

Mountain    Aneroid    Barometers,    compensated    for   temperature,    with 
brass  cases  and  silvered  dials,  in  morocco  cases. 


3303 

No.  PRICE       POST. 

3300  Pocket  Aneroid,  2  inches  diameter,  altitude  scale  to 

3,000  feet,  by  each  10  feet. $18.00     $0.20 

3301  Pocket  Aneroid,  2  inches  diameter,  altitude  scale  to 

5,000  feet,  by  each  20  feet .*. 1 7.00         .20 

3302  Pocket  Aneroid,  2  inches  diameter,  altitude  scale  to 

10,000  feet,  by  each  50  feet 18.00         .20 

3303  Pocket  Aneroid,  2  inches  diameter,  altitude  scale  to 

15,000  feet,  by  each  100  feet 19.00        .20 

3304  Pocket  Aneroid,  2  inches  diameter   (nickeled  hunt- 

ing-case and  omitting  morocco  case),  altitude  scale 

to  6,000  feet,  by  each  50  feet 22.00  .20 

3306  Pocket  Aneroid,  2f  inches  diameter,  altitude  scale 
to  10,000  feet,  by  each  50  feet,  with  thermometer 
and  opposite  side  with  pocket  compass 27.00  .30 

3308  Pocket  Aneroid,  2|  inches  diameter,  altitude  scale 
to  16,000  feet,  by  each  50  feet,  with  thermometer 
and  opposite  side  with  pocket  compass 29.00  .30 


W.  &-  L.  E.   GURLEY,   TROY,  N.    Y.  421 

No.  PRICE        POST. 

3310     Pocket  Aneroid,  2f  inches  diameter,  altitude  scale 

to  3,000  feet,  by  each  10  feet $19.00     $0.25 

3312  Pocket  Aneroid,  2f  inches  diameter,  altitude  scale 

to  5,000  feet,  by  each  20  feet 18.00         .25 

3313  Pocket  Aneroid,   2|  inches  diameter,  altitude  scale 

to  8,000  feet,  by  each  20  feet 18.00         .25 

3314  Pocket  Aneroid,  2f  inches  diameter,  altitude  scale 

to  10,000  feet,  by  each  50  feet 19.00         .25 

3315  Pocket  Aneroid,  2|  inches  diameter,  altitude  scale 

to  12,000  feet,  by  each  50  feet 19.00  .25 

3310  Pocket  Aneroid,  2f  inches  diameter,  altitude  scale 

to  16,000  feet,  by  each  50  feet 20.00  .25 

3318  Pocket  Aneroid,  2|  inches  diameter,  altitude  scale 

to  20,000  feet,  by  each  100  feet '.....  22.00  .25 

3322  Pocket  Aneroid,  2|  inches  diameter,  altitude  scale 

to  10,000  feet,  by  each  50  feet,  and  thermometer..  22.00  .25 
3324  Pocket  Aneroid,  2f  inches  diameter,  altitude  scale 

to  16,000  feet,  by  each  50  feet,  and  thermometer..     23.00         .25 

3329  Pocket  Metric  Aneroid,  2f  inches  diameter,  altitude 

scale  to  1,500  meters,   reading  to  5  meters,  and 

pressure  scale  reading  to  \  millimeter 18.00         .25 

3330  Pocket  Metric  Aneroid,  2|  inches  diameter,  altitude 

scale  to  3,000  meters,  reading  to  10  meters,  and 

pressure  scale  reading  to  1  millimeter 19.00         .25 

3332  Pocket  Metric  Aneroid,  2f  inches  diameter,  altitude 
scale  to  5,000  meters,  reading  to  20  meters,  and 
pressure  scale  reading  to  2  millimeters 20.00  .25 

3336  Plain  Aneroid,  no  altitude  scale,  5  inches  diameter, 
with  thermometer  and  open  face  to  show  mechan- 
ism, for  parlor  use 15.00 

3338  Plain  Aneroid,  no  altitude  scale,  6^  inches  diameter, 
and  with  two  thermometers  reading  to  scales  of 
Fahrenheit,  Reaumur,  and  Celsius,  and  open  face 
to  show  mechanism,  for  parlor  use 18.00 

3340     Self-recording   Aneroid    Barometer,    with    attached 

thermometer.    In  mahogany  case  with  glass  front.  .      45.00 

The  cylinder  makes  a  complete  revolution  in 
seven  days,  and  thus  each  diagram  gives  a  baro- 
metric record  for  one  week. 


The  graduated  spaces  on  the  altitude  scales  of  Barom- 
eters No.  3300  to  3332  can  be  subdivided  by  the  eye  or  by 
using  a  magnifier,  and  thus  a  closer  reading  obtained. 


A  leather  sling  case  for  Barometers  Nos.  3306  to  3332, 
and  omitting  the  morocco  case,  costs,  extra,  $1.50. 


422  ^  &>  L.  E.   GURLEY,   TROY,  N.    Y. 

SURVEYING   AND   MINING   ANEROIDS 

BRONZED  CASES,  SILVERED    DIALS  WITH    REVOLVING    MAGNIFIER.       COM- 
PENSATED   FOR    TEMPERATURE.       IN    LEATHER    SLING    CASES  ' 
No.  PRICE        POST. 

3350  Surveying  Aneroid,  3  inches  diameter,  altitude  scale 
to  6,000  feet,  by  each  20  feet  and  by  vernier  to  2 

feet $42.00 

3352  Surveying  Aneroid,  3  inches  diameter,  with  altitude 
scale  to  10,000  feet,  by  each  50  feet  and  by  vernier 
to  5  feet 45.00 

3354  Surveying  Aneroid,  3  inches  diameter,  with  altitude 

scale  to  15,,000  feet,  by  each  50  feet  and  by  vernier 

to  5  feet 48.00 

3355  Mining   Aneroid,    3    inches   diameter,    arranged   to 

register  2,000  feet  below  sea-level  to  4,000  feet 
above,  by  each  20  feet  and  by  vernier  to  2  feet.  .  42.00 

3360  Surveying  Aneroid,  5  inches  diameter,  with  altitude 
scale  to  5,000  feet,  by  each  10  feet  and  by  vernier 
to  1  foot 50.00 

3362  Surveying  Aneroid,  5  inches  diameter,  with  altitude 
scale  to  10,000  feet,  by  each  20  feet  and  by  vernier 
to  2  feet 52.00 

3364  Surveying  Aneroid,  5  inches  diameter,  with  altitude 
scale  to  15,000  feet,  by  each  20  feet  and  by  vernier 
to  2  feet 54.00 

3366  Surveying  Aneroid,  5  inches  diameter,  with  altitude 
scale  to  20,000  feet,  by  each  50  feet  and  by  vernier 
to  5  feet 57.00 

The  Surveying  and  Mining  Aneroid  has  been  constructed  especially 
for  the  use  of  Surveyors  and  Engineers,  for  ascertaining  slight  variations 
in  gradients,  levels,  etc.,  and  from  its  extreme  sensitiveness  will  be  found 
of  considerable  utility  in  Mining  and  Surveying  work  generally. 

The  Vernier  Scale  is  moved  by  rack  and  pinion,  and  the  magnifier 
which  rotates  on  the  outer  circumference  of  the  instrument  facilitates  the 
reading  of  the  vernier. 

A  Treatise  on  the  Aneroid  Barometer  ;  its  construction  and  use.  Illus- 
trated. 50  cents. 

With  the  exception  of  Nos.  3336  to  3340,  all  the  Barometers  mentioned 
on  pages  420  to  422  are  furnished  with  a  rating  card,  showing  the  result 
of  tests  in  comparison  with  our  standard  mercurial  barometer. 


W. 


L.  E.   GURLEY,   TROY,  N.    Y. 


423 


TO   USE   THE   ANEROID,    WITH    ALTITUDE 
SCALE 

Find  the  height  in  feet  at  first  station  and  subtract  this  from  the  height 
in  feet  at  second  station.  If  the  mean  temperature  is  greater  or  less  than 
50°  F.,  apply  correction  for  temperature  as  hereafter  given. 

Example  : 

Aneroid  at  Station  A,  1,800  feet.     Thermometer,  50°. 
Aneroid  at  Station  B,  800  feet.     Thermometer,  70°. 

The  approximate  height  is  1,000  feet.     The  sum  of  the  temperatures  is 
120.     A  correction  of  -|-  20  is  therefore  applied.     This  is  20  feet. 
The  difference  of  elevation  is  therefore  1,000  -f  20  =  1,020  feet. 


TO     FIND     THE     RELATIVE     HEIGHT     OF     TWO 
GIVEN   PLACES 

Take  a  reading  of  the  Aneroid  at  first  station  ;  subtract  from  this  the 
reading  at  second  station.  The  product  multiplied  by  9  will  give  the 
difference  of  altitude  in  feet,  thus  : 

First  Station,  30.20  ;  Second  Station,  29.99  ;  30.20  —  29.99  =  .21  ; 
.21  X  900  (or  21  X  9)  =  189  feet  =  difference  of  altitude. 

This  under  ordinary  pressures  and  with  a  temperature  about  50°  F. 
will  give  good  results.      If  the  temperature  is  over  70°   F.  multiply  by  10. 
The  table  prepared  by  Mr.  Symons  is  more  strictly  accurate  : 


MEAN  TEMPERATURE  ' 

30° 

40° 

50° 

60° 

70° 

80° 

Mean  pressures,  27  inches.  . 
Mean  pressures,  28  inches.. 
Mean  pressures,  29  inches.. 
Mean  pressures,  30  inches.  . 

9.7 
9.3 
9.0 

8.7 

9.9 
9.5 
9.2 

8.9 

10.1 
9.8 
9.4 
9.1 

10.3 
10.0 
9.6 
.9.3 

10.5 
10.2 
9.8 
9.5 

10.8 
10.4 
10.0 
9.7 

Roughly  speaking,  the  barometer  falls  one  inch   for  every  900  feet  of 
ascent ;  or  at  mean  atmospheric  pressure  in  this  latitude, 

Above  sea-level  917  feet,  the  barometer  falls 1  inch. 

Above  sea-level  1,860  feet,  the  barometer  falls 2  inches. 

Above  sea-level  2,830  feet,  the  barometer  falls 3  inches. 

Above  sea-level  3,830  feet,  the  barometer  falls 4  inches. 

Above  sea-level  4,861  feet,  the  barometer  falls 5  inches. 


424 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 


ANEMOMETERS 

FOR    MEASURING   THE    1'RESSURE   AND  VELOCITY    OF   CURRENTS   OK    AIR    IN 
COAL   MINES,  AND   VENTILATORS,   FLUES,    ETC.,    OF    PUBLIC    BUILDINGS 

"  Biram's." — For  registering  the  velocity  of  currents  of  air  in  mines, 
tunnels,  etc.,  by  means  of  a  light  fan,  the  revolutions  of  which  are  recorded 
on  a  dial  in  the  center  of  the  instrument. 

This  instrument  placed  in  the  passage  of  a  mine  registers  automatically 
the  rate  at  which  the  air  is  traveling  through  it,  and  a  simple  observation 
will  detect  any  slackening  of  the  current  arising  from  obstruction  of  the 
ways,  or  want  of  attention  at  the,  ventilating  furnace,  or  fan-wheel. 

We  furnish  a  rating  card  with  each  Anemometer,  showing  the  frictior 
constant  to  be  added  in  every  computation,  which  is  ascertained  by  us  by 
actual  experiment. 


No. 
3380 

3382 
3383 
3384 


3380 

PRICE  POST. 
Biram's  Anemometer,  3  inches  diameter,  reading  to 

1,000  feet, 'with  disconnector,  in  morocco  case.  . .  $20.00  $0.30 
Biram's  Anemometer,  4  inches  diameter,  reading  to 

1,000  feet,  with  disconnector,  in  wood  case 19.00  .40 

Biram's  Anemometer,  4  inches  diameter,  reading  to 

100,000  feet,  with  disconnector,  in  wood  case.  ...  21.00  .40 
Biram's  Anemometer,  6  inches  diameter,  reading  to 

1,000  feet,  with  disconnector,  in  wood  case 21.00  .60 

Biram's  Anemometer,  6  inches  diameter,  reading  to 

100,000  feet,  with  disconnector,  in  wood  case.  ...     23.00         .60 


IV.  &  L.  E.   GURLEY,   TROY,  N.    Y.  425 

No.  PRICE       POST. 

3388     Biram's  Anemometer,  6  inches  diameter,  reading  to 

10,000,000  feet,  with  disconnector,  in  wood  case.  .   $33.00     $0.60 
3390     Biram's  Anemometer,  watch  pattern,  hunting-case, 

very  sensitive,  reading  to  1,000  feet 30..  00         .18 

Pocket  Size,  2  inches  diameter. — Is  made  in  the  form  of  a  watch.  The 
top  and  bottom  of  the  case,  when  opened,  form  a  base  for  the  instrument, 
and  a  check-spring  passing  through  the  pendant  acts  as  a  stop  to  the  move- 
ment, on  being  pressed  by  the  finger  at  the  expiration  of  the  time  necessary  to 
make  the  observation.  The  movement  is  jeweled  at  four  points.  The 
outer  circle  of  divisions  on  the  dial  records  by  single  feet  up  to  one  hun- 
dred ;  the  smaller  dial  continues  the  enumeration  up  to  one  thousand  feet. 


HOW   TO   USE   THE   ANEMOMETER 

The  Anemometer  consists  of  a  series  of  vanes,  which  revolve  with  the 
action  of  the  air-current,  the  number  of  revolutions,  or  numbers  propor- 
tioned to  the  revolutions,  being  registered  by  a  pointer  on  the  face  of  a  dial, 
forming  part  of  the  instrument  itself.  An  observer  has  only  to  record  the 
position  of  the  several  indices  at  the  first  observation,  by  writing  the  lower 
of  the  two  figures  on  the  respective  circles,  between  which  the  index 
points,  in  their  proper  order,  and  deduct  the  amount  from  their  position  at 
the  second  observation,  to  ascertain  the  velocity  of  the  air  which  has  passed 
in  the  interval.  This,  multiplied  by  the  area  in  feet  of  the  passage  where 
the  instrument  is  placed,  will  show  the  number  of  cubic  feet  which  has 
passed  during  the  same  period. 

Thus,  suppose  the  observation  of  one  minute  gives : 

Second  reading 525 

First  reading .     225 

300 
Add  correction,  say 30 

.  330 

Size  of  passage  in  feet,  10  x  5  x  330  =  16,500  feet  per  minute. 
The  correction  added  above  is  the  value  of  the  constant  of  friction, 
which  must  be  found  for  each  machine  by  actual  experiment. 


TO    FIND   THE   VELOCITY   OF   THE   AIR 
IN    THE    PASSAGE 

Proceed  thus  :  Suppose  the  Anemometer  indicates  330  feet  per  minute. 
330  -*-  88  =  3.75,  or  3f  miles  per  hour,  88  being  a'?th  of  a  mile. 

To  ascertain  the  force  of  the  air-current,  multiply  the  square  of  the 
velocity  of  the  air  in  feet  per  second  by  .0023. 


426 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y. 
AIR   METERS 


3397 
No.  PRICE       POST. 

3396  Air   Meter,   with  disconnector,  fan-wheel  2|  inches 

diameter,  two  dials  reading  to  1,000  feet f  19.50     $0.35 

3397  Air   Meter,    with  disconnector,  fan-wheel  2£  inches 

diameter,  six  dials  reading  to  10,000,000  feet 21.75         .35 

The  portable  Air  Meter  is  for  the  measurement  of  currents  of  air 
through  mines,  tunnels,  sewers  and  the  ventilators  of  hospitals,  public 
buildings,  etc.  The  indications  are  obtained  by  means  of  a  delicately 
poised  fan-wheel,  the  recordings  being  commenced  by  the  long  hand, 
which  traverses  the  extreme  outer  circumference  of  the  main  dial  for  the 
passage  of  one  hundred  feet  of  air.  The  enumeration  is  continued  up  to 
ten  millions  of  feet  (say  1,894  miles)  by  a  series  of  smaller  dials  as 
shown  in  the  illustration.  A  Disconnector,  projecting  from  the  band 
of  the  instrument,  opposite  the  fan-wheel,  serves  to  throw  the  mechanism 
out  of  gear,  and  arrest  its  action,  when  required.  The  instrument  is 
packed,  with  universal  jointed  socket-holder,  in  a  box  about  four  inches 
square. 


W.  <5r»  L.  E.   GURLEY,   TROY,  N. 


427 


FIELD-GLASSES   AND   BINOCULAR   TELESCOPES 

The  Field-glasses  here  described  are  of  the  best  quality  and  especially 
adapted  for  tourists,  engineers,  military  service,  or  general  field  use.  They 
are  achromatic,  and  are  metal  body  covered  with  morocco,  and  have  a 
case  with  strap.  Some  are  designated  by  the  diameter  of  the  objectives, 
in  French  lines,  eleven  lines  being  equal  to  one  inch. 


3400  3442  with  focusing  attachment 

FIELD-GLASS,    GOOD   QUALITY 

No.  PRICE        POST. 

3400     Body,  4f  inches  long  ;  objectives,  21  lines $7.00     $0.30 

3402     Body,  6^  inches  long  ;  objectives,  26  lines 9.00         .40 

FIELD-GLASS,    FINE   QUALITY 

3407  Body,  5|  inches  long ;  objectives,  24  lines $14.00     $0.45 

3408  Body,  6£  inches  long  ;  objectives,  26  lines  ........        15.00         .50 

JENA   FIELD-GLASS 

NEW   STYLE  AND   SUPERIOR 

3410  Body,  6  inches  long  ;  objectives,  26  lines $19.00     $0.50 

3411  Body,  5f  inches  long  ;  objectives,  24  lines  and  with 

hinge  adjustment 20.00         .45 

U.   S.  ARMY    SIGNAL   SERVICE   FIELD-GLASS 

VERY   SUPERIOR 

3413  Body,  6|  inches  long  ;  objectives,  24  lines $18.00     $0.45 

3414  Body,  Of  inches  long  ;  objectives,  26  lines 20.00         .50 

3416     Body,  6f  inches  long  ;  objectives,  24  lines  and  with 

hinge  adjustment 20.00         .45 


428  W.' &>  L.  E.   GURLEY,    TROY,  N.    Y. 

GOERZ-TRIEDER-BINOCULAR 

NEW   STYLE,  GREAT   POWER 

No.  PRICE 

3418  Trieder- Binocular,  No.  30,  power  9  times |54.00 

3419  Trieder- Binocular,  No.  40,  power  12  times 62.00 

BINOCULAR    TELESCOPE 

OLD   PATTERN 

3422  Body,  5£  inches  long  ;    objectives,   8  lines  ;   power 

10  times $27.00     $0.35 

3423  Body,  9£  inches  long  ;    objectives,  16  lines  ;    power 

16  times 45.00        .75 

3424  Body,  11  inches  long;    objectives,  19  lim-s  ;    power 

20  times 50.00         .90 

JENA   BINOCULAR   TELESCOPE 

These  binoculars  have  great  power,  a  hinge  ad- 
justment, and  a  device  for  quick  focusing. 

3426  Body,  6f  inches  long  ;  objectives,  11  lines  ;  power 

18  times. $36.00  $0.60 

3428  Body,  1\  inches  long  ;  objectives,  15  lines  ;  power 

24  times 45.00  .  .76 

RANCHMAN'S    GLASS 

SUPERIOR   QUALITY 

3430     Body,  Gf  inches  long  ;  objectives,  26  lines $18.00     $0.50 

PANERGETIC    GLASS 

ALUMINUM    BODY,  NEW   STYLE  AND   SUPERIOR 

3434  Body,  4  inches  long  ;  objectives,  21  lines $23.00     $0.30 

3435  Body,  4£  inches  long  ;  objectives,  24  lines 26.00         .:-]5 

3438     Body,  4^  inches  long ;  objectives,  24  lines,  and  with 

hinge  adjustment 31.00         .35 

BAUSCH   &    LOMB-ZEISS    STEREO    BINOCULAR 

f  LATEST   STYLE  AND   SUPERIOR 

3442  Stereo  Binocular,  No.  8,  power  8  times $47.50     $0.35 

3443  Stereo  Binocular,  No.  12,  power  12  times 67.50         .40 

If  with   focusing    attachment,    as   shown   on 
page  427,  add  $5.00  extra. 

BAUSCH  &  LOME   PLAIN    BINOCULAR 

SUPERIOR   QUALITY 

3446  Plain  Binocular,  No.  8,  power  8  times. $40.00     $0.35 

3447  Plain  Binocular,  No.  10£,  power  10J  times 48.00         .40 

If  with  focusing  attachment,  add  $5.00  extra. 


W.  &»  L.  E.   GURLEY,   TROY,  N.    Y.  429 

PRISM   TERRESTRIAL   TELESCOPE 


3470 


No.  PRICE 

3470  Telescope  21  \  inches  long,  objective  2  inches  in  diameter, 
two  eyepieces  with  powers  of  24  and. 40  times;  folding 
tripod.  The  telescope  and  tripod  are  contained  in  a 

leather- covered  carrying  case,  24x6£x41  inches $80.00 

This  Porro  Prism  instrument  represents  the  highest  develop- 
ment in  terrestrial  telescopes.  It  bears  the  same  relation 
to  the  ordinary  telescope  which  the  prism  binocular  bears 
to  the  old  style  field-glass.  The  telescope  tube  and  alt- 
azimuth mountings  are  of  aluminum,  and  the  workman- 
ship is  superior  in  every  respect. 


430 


.  &  L.  E.   GURLEY,   TROY,  N.    K 
ACHROMATIC   TELESCOPES 


3475 


PRICE        POST. 


No. 

3475  Telescope,  with  3  draws,  Yl\  inches  drawn  out,  6£ 

inches  shut,  objective  1  inch  in  diameter,  power 

13  times $2.50    $0.20 

3476  Telescope,  with  3  draws,  18f  inches  drawn  out,  7 

inches    shut,    objective    \\   inches    in    diameter, 

power  16  times 3.60         .25 

3477  Telescope,  with  3  draws,  23|  inches  drawn  out,  8| 

inches    shut,    objective    If    inches    in    diameter, 

power  20  times 5.00         .30 

3478  Telescope,   with  3  draws,  30  inches  drawn  out,  10 

inches    shut,    objective    If   inches    in    diameter, 

power  25  times 7.00         .40 

3479  Telescope,  with  4  draws,  37  inches  drawn  out,  11 

inches    shut,    objective    If   inches    in    diameter, 

power  35  times 10.00         .65 

3480  Telescope,  with  4  draws,  42  inches  drawn  out,  11^ 

inches    shut,    objective   2|   inches    in    diameter, 

power  40  times 17.00         .85 

3481  Telescope,  with  4  draws,  48  inches  drawn  out,  13£ 

inches    shut,    objective   2|   inches    in    diameter, 
power  50  times 30.00 


3485     See  page  431. 


W.  &  L.  E.   GURLEY,    TROY,  N.    Y.  431 

TOURISTS4  ACHROMATIC   TELESCOPES 

No.  PRICK        POST. 

3485  Telescope,  with  brass  body  covered  with  morocco  ; 

three  draws,  17  inches  drawn  out,  6  inches  shut ; 
objective  1^  inches  in  diameter ;  sun-shade ; 
leather  caps  to  cover  eyepiece  and  objective, 
and  shoulder  strap.  Power  20  times $  8.00  $0.20 

3486  Telescope,    same   as  No.    3485,   but   is   21    inches 

drawn    out,  7  inches    shut  ;    objective  If  inches 

in  diameter.      Power  25  times 11.00         .30 

3487  Telescope,   same   as   No.    3485,    but   is   24   inches 

drawn  out,   9  inches    shut ;    objective  If  inches 

diameter.     Power  30  times 15.00         .40 

3488  Telescope,  same  as  No.  3485,  but  has  four  draws, 

36  inches  drawn   out,  10  inches  shut ;    objective 

2  inches  in  diameter.      Power  35  times 22.00         .60 

3492     Rifle  Spy-glass,  lOf  inches  drawn  out ;  body  covered 

with  morocco ;  objective  \  inch  in  diameter. 

Power  10  times 2.50  .15 

3494  Wooden  Tripod  Stand,  with  vertical  and  horizontal 
motion,  upon  which  to  place  a  telescope.  A  useful 
article,  as  a  telescope  of  much  power  cannot  be 
held  in  the  hand  with  sufficient  steadiness 5.00 

3496  Brass  Clamp  with  Gimlet  Screw,  to  fasten  a  tele- 
scope to  a  post  or  tree  ;  sizes  to  fit  telescopes 
Nos.  3475  to  3488.  Price  according  to  size 
$1.50,  2.00,  2.50,  3.00,  4.00  and  5.00  .15 

ASTRONOMICAL   TELESCOPES 

3502  Astronomical  Telescope,  polished  brass  body,  35 
inches  long,  mounted  on  brass  tripod  stand,  achro- 
matic objective  2|  inches  in  diameter,  one  ter- 
restrial eyepiece,  power  50  times,  one  celestial 
eyepiece,  power  100  times,  rack  and  pinion  for 
focusing.  In  box  with  lock 75.00 

3506  Astronomical  Telescope,  polished  brass  body,  35 
inches  long,  rack  and  pinion  for  focusing,  achro- 
matic objective  2J  inches  in  diameter,  terres- 
trial eyepiece,  power  40  times,  celestial  eyepiece 
with  darkener,  power  80  times,  wooden  tripod 
with  horizontal  and  vertical  motion.  In  box  with 
lock,  for  receiving  the  body  and  eyepieces 75.00 

3508  Astronomical  Telescope.  Same  as  No.  3506,  but 
with  body  40  inches  long,  achromatic  objective 

3  inches  in   diameter,  terrestrial    eyepiece,   power 
55  times,  celestial  eyepiece  with  darkener,  power 

110  times.     In  box  with  lock 100.00 


432  W.  &  L.  £-   GURLEY,   TROY,  N.    K 

POCKET   MAGNIFIERS 


3520  3526 

RUBBER    CASE,    pVAL    FORM,    1    DOUBLE-CONVEX    LENS 


No. 
3520 
3521 


PRICE        POST. 
1-inch |0.40    $0.02 


No. 


PRICE        POST. 


3522  "4-inch $0.70    $0.03 

3523  2-inch..  1.15         .12 


1  j-inch (50         .02 

RUBBER    CASE,  OVAL   FORM,    2    DOUBLE-CONVEX    LENSES 

3626     |  and  1-inch..     .65         .03    |    3528     Handle-inch,    1.10 


.12 


3530 

RUBBER   CASE,    BELLOWS   FORM,    1    DOUBLE-CONVEX   LENS 

3530     f-inch -      .40         .02    |   3532     1-inch 60 

RUBBER   CASE,    BELLOWS    FORM,    2    DOUBLE-CONVEX    LENSES 

3534     fandf-inch.        .60         .02       3536     f  and  1 -inch.  .    1.00 


.02 
.12 


W.  fr  L.  E.   GURLEY,   TROY,  N.    Y.  433 

RUBBER   CASE,    BELLOWS   FORM,    3   DOUBLE-CONVEX   LENSES 

No.  PRICE      POST.  I    No.  PRICE       POST. 

3538     £,f,andf-in.     $0.80    $0.03 1 3539     £,$,  andl-in.     $1.30    $0.12 

3542  White  Celluloid  Case,  oval  form,  one  1-inch  double- 

convex  lens. .80         .02 

3543  White  Celluloid  Case,  oval  form,  one  1^-inch  double- 

convex  lens 1.00  .03 

3550     German  Silver  Case,  oval  form,  one  1-inch  double- 
convex  lens .75  .04 

3555     Microscope,  brass  mounted,  on  three  legs,  adjustable. .  .75  .05 


3560 


3560  Linen  Prover,  for  counting  threads  in  linen  fabrics, 

brass  mounted,  ^-inch  square  open  space 

3561  Linen  Prover,  for  counting  threads  in  linen  fabrics, 

brass  mounted,  y^-inch  round  open  space 

3562  Linen  Prover,  for  counting  threads  in  linen  fabrics, 

brass  mounted,  ^-inch  round  and  J-inch  square 
open  spaces 

3565  Linen  Prover,  for  counting  threads  in  linen  fabrics, 

brass  mounted,  1-inch  square  open  space 2.00 

3566  Coddington  Lens,  brass  mounted,  small 1.00 

3567  Coddington  Lens,  brass  mounted,  medium 1.35 

3568  Coddington  Lens,  brass  mounted,  large 1.75 

3569  Aplanatic  Magnifier,  high  power,  and  flat  field 1.00 


.60        .02 
.50        .02 


.60        .02 


.13 
.12 
.14 
.15 
.12 


3670 


434 


W.  &  L.  E.   GURLEY,   TROY,  N.    Y. 


No.  PRICE        POST. 

3570  Coddington  Lens,  nickeled  frame  and  cover,  £-inch 

diameter $1.50     |0.12 

3571  Coddington  Lens,  nickeled  frame  and  cover,  f-inch 

diameter ' 1.75         .12 

3572  Coddington  Lens,  nickeled  frame  and  cover,  1-inch 

diameter - 2.00         .12 

3575     Aplanatic  Triplet,  nickeled  frame  and  cover,  supe- 
rior quality,  giving  perfect  definition,  J-inch  focus, 

power  20  times 5.00         .12 

3577     Aplanatic  Triplet,  nickeled  frame  and  cover,  supe- 
rior quality,  giving  perfect  definition,  1-inch  focus, 

power  10  times 5.00         .12 

Lenses  Nos.  356G  to  3577  have  extra  power 
and  definition  for  examining  minerals,  ore,  rock, 
flowers,  etc. 


READING-GLASSES 


No. 

3585 
3586 
3587 


READING-GLASS,  METAL   FRAME,  DOUBLE-CONVEX    LENS 


PRICK  POST. 

2  inches  diam..|0.80  $0.05 
"2\  inches  diam.    1.00  .13 

3  inches  diam..   1.50  .15 


No.  PRICK 

3589  4  inches  diam.. $2. 50 

3591  5  inches  diam..   4.00 

3593  6  inches  diam..  G.OO 


POST. 

$0.18 
.35 
.40 


READING-GLASS,    METAL   FRAME,    TWO   PLANO-CONVEX   LENSES 

3595  2  inches  diam..   1.25         .15    I  3597     3  inches  diam..   2.25 

3596  2 \  inches  diam.   1.50         .18    |  3598     3£  inches  diam.   3.25 


.20 
.25 


READING-GLASS,    OBLONG   METAL   FRAME,    DOUBLE-CONVEX   LENS 

3GOO     2f  x  lynches..   1.50         .13      3602     3xl    inches..  2.00         .18 


3601     3    x  finches..   1.75         .15   j  3603     3|  x  If  inches..  2.50         .20 


W.  &  L.  E.   GURLEY,   TROY,  N.    K 


435 


POCKET    SPIRIT-LEVELS.      French  Make 


PLAIN    VIALS,    MOUNTED    IN    BRASS 


No. 

3650  3  inches. 

3651  6  inches. 


PRICE  POST. 
,$0.50  $0.06 
,  1.00  .18 


No. 
3652 
3653 


9  inches . 
12  inches. 


PRICE  POST. 
.$1.50  $0.23 
.  2.00  .28 


POCKET    SPIRIT-LEVELS 


A  superior  article.     Our  own  make,  with  ground  and  graduated  vial, 
mounted  in  brass  and  adjustable,  and  in  wood  case. 


3660 

3660     6  inches $3.50    $0.18   |   3664     10  inches $4.50 

LEVEL-VIALS,    UNMOUNTED 

OUR   OWN    MAKE,    AND    EVERY    ONE   TESTED 


$0.25 


3675 

3675     Ground  and  Graduated  Level-Vials,  unmounted :  * 

\\  inches $0.45     2    inches $0.50     2£  inches  . .  .   $0.60 

3"  inches 75     3£  inches 90     4    inches 1.05 

4£  inches 1.00     5    inches 1.45     5£  inches 1.65 

6    inches. 1.80     6£  inches 2.00     7"  inches 2.25 

3690     Ground  Level-Vials,  not  graduated,  unmounted :  * 

1  to  \\  inches.     .35     2    inches 40     2£  inches 50 

3    inches 60     3£  inches 75     4    inches 90 

4£  inches. 1.20     5    inches 1.25     Scinches 1.40 

6    inches 1.50     6£  inches 1.65     7    inches 1.85 

3710     Plain  Level -Vials,  not  graduated,  unmounted:* 

1  to  1  \  inches.     .10     2    inches 12     2£  inches 13 

3    inches 15     3£  inches 18     4    inches 20 

4^  inches 25     5    inches. ....      .35     5^  inches 40 

6    inches ..50     6|  inches 60     7    inches 75 

If  sent  by  mail,  the  postage  on  uncounted  level-vials,  1%  to  7  inches,  will 
be  3  cents  to  18  cents,  according  to  size. 

*  When  ordering,  mention  the  extreme  length  and  diameter  required, 


436 


W.  &  L.  E.   GUKLEY,   TROY,  N. 


CARPENTERS'   AND   MASONS'   SPIRIT-LEVELS 

No.  PRICE 

3726  Cherry  Body,  26  inches  long,  with  level  and  plumb  vials.  .  .     $0.75 

3727  Cherry  Body,  28  inches  long,  with  level  and  plumb  vials.  . .         .85 

3730  Cherry  Body,  26   inches   long,   brass  ends,   both   vials  ad- 

justable         1.25 

3731  Cherry  Body,  28   inches  long,  brass  ends,  both  vials  ad- 

justable   .  1.35 

3734  "Handy"  Plumb  and  Level,  cherry  body,  26  inches  long, 

brass  ends,  adjustable  vials 1.50 

3738  Mahogany  Body,  28  inches  long,  brass  ends,  adjustable  vials  .  1. 75 

3740  Iron  Frame,  22  inches  long,  adjustable  vials.  Superior.  ...  3.50 

OILSTONES 

PRICE       POST. 

3765  Arkansas  Oilstones,  fine  quality  for  drawing-pens.  .     $0.25     $0.03 

3766  Arkansas   Oilstones,    fine    quality,    3 \  x  1    inch,    in 

mahogany  block  with  cover .75  .10 

3768  Arkansas  Oilstones,  fine  quality,  5x2  inches,  in 

mahogany  block  with  cover 2.00  .25 

3773  Washita  Oilstones,  common,  3£xl  inch,  in  cherry 

block  with  cover 45  .10 

3775  Washita  Oilstones,  common,  5x2  inches,  in  cherry 

block  with  cover .75         ,20 


L.  E.   GURLEY,   TROY,  N.    Y. 


437 


No.  .  PRICK 

3780  Trammel  Points,  small,' No.  1,  see  page  436 $1.00 

3781  Trammel  Points,  medium,  No.  2 1.25 

3782  Trammel  Points,  large,  No.  3 1.65 

3800     Machinists'    Tools,     Lathe    and    Drill-Chucks   and 

Drills,  Steel  Squares  and  Gauges,  Brass  Tubing 
and  Wire,  Sheet  Brass  and  German  Silver,  Stubs' 
Steel  Wire,  etc.,  etc.,  at  manufacturers'  prices. 


POST. 

$0.15 

.20 

.25 


STEEL    MAGNETS 


3850 


No. 

3850  2  inches  .  .  . 

3852  3  inches  .  . . 

3854  4  inches  .  .  . 


PRICE 

$0.12 

.20 

.35 


POST. 
$0.03 

.04 

.06 


No. 
3856 
3858 
3860 


5  inches 

6  inches 

7  inches 


PRICK  POST. 

$0.50  $0.10 

.75  .13 

1.10  .20 


BRASS   BLOW-PIPES 


PLAIN 

3865       8  inches...  $0.15  $0.05 

3867     10  inches  ...  .20  .06 

3869     12  inches  . .  .25  .07 


WITH    BULB 

3875       8  inches  . . .     $0.30  $0.05 

3877     10  inches  ...         .35  .06 

3879     12  inches  ...         .40  .07 


3890 
3892 
3894 
3896 
3910 
3912 


THERMOMETERS   IN   JAPANNED   CASES 

OPEN   AIR    SCALE 


COMMON 

6  inches  . .  .     $0.40    $0.06 

8  inches  ...  .50  .10 
10  inches...  .60  .12 
12  inches...  .70  .18 

8  inches,  fine  quality,  with  b 
10  inches,  fine  quality,  with  boiling  scale 


FINE   QUALITY 


3900       7  inches  .  .  . 
3901       8  inches  .  .  . 
3903     10  inches  .  .  . 
3905     12  inches  .  .  . 
>iling  scale  
>iling  scale  .  . 

$0.60    $0.08 
.75         .12 
1.00         .15 
1.26         .25 
•  90         .12 
1.25        ,25 

438  W-  &  L.  E.   GURLEY,    TROY,.  N.    K 


THERMOMETERS   WITH    FANCY  WOOD   BACKS 

OPEN   AIR    SCALE 
OAK    BACK  MAHOGANY    BACK 


No.  /  PRICE  POST. 

3920  8  inches...  $1.00  $0.18 

3922  10  inches...  1.35  .20 

3924  12  inches...  2.00  .25 


No.  PRICE        POST. 

3930       8  inches...     $1.25     $0.18 
3932.    10  inches..          1.50         .20 


3935  Pocket  Thermometer,  folding  wood  case,  5-inch. . .  .        1.00         .12 

3936  Pocket  Thermometer,  mahogany  case,  6-inch,  revers- 

ible scale,  fine  quality 1.85         .15 

3938     Pocket  Thermometer,  in  metal  tube,  nickel -plated, 

5-inch &5         .12 

3940  Window  Thermometer,  8-inch,  plate-glass,  30°  be- 

low zero,  with  brackets. 1.25         .25 

3941  Window  Thermometer,  same  as  No.  3940,  but  50° 

below  zero 1.50  .25 

3943  Brewers'  Copper  Case  Thermometer,  12-inch  and 

deep  cup../ - 2.50  .30 

3945  Dairy  Thermometer,  all  glass,  floating,  8-inch 35  .07 

3950  Chemical  Thermometer,  all  glass,  60°  to  300°, 

14-inch 3.75  .25 

3952  Chemical  Thermometer,  all  glass,  60°  to  400°, 

14-inch 4.00  .25 

3954  Chemical  Thermometer,  all  glass,  60°  to  500°, 

14-inch. . ,  4.25        .25 


SELF-REGISTERING   THERMOMETERS 

3960     Maximum  Thermometer,  10-inch,  wood  back $2.75     $0.20 

3962     Maximum   Thermometer,    U.    S.    Weather    Bureau 

pattern,  12-inch,  aluminum  back 5.00         .20 

3965     Minimum  Thermometer,  10-inch,  wood  back 2.25         .20 

3967     Minimum    Thermometer,   U.    S.    Weather    Bureau 

pattern,  12-inch,  aluminum  back 4.25         .20 

3970     U.  S.  Weather  Bureau  set  of  Maximum  and  Mini- 
mum  Thermometers,    12-inch,    aluminum    back, 

and  mounted  together  on  one  wood  back 9.50         .50 

3975     Mason's  Hygrometer,  consisting  of  dry  and  wet  bulb 

thermometers  mounted  on  one  wood  back 2.50         .30 

AH  these  Thermometers  have  the  Fahrenheit  scale. 


W.  &>  L.  E.   CUR  LEY,   TROY,  N.    Y.  439 

RAIN  GAUGES 

No.  PRICE 
3980  Smithsonian  Rain  Gauge,  of  capacity  for  1-inch 
rainfall.  This  gauge  is  made  of  brass  and  is  the 
most  simple  in  its  construction  of  any  now  in  use. 
It  has  a  measuring-stick  which  reads  to  lOths  and 
lOOths  of  inches ;  also  a  wooden  cylinder  to  insert 
in  the  ground  for  the  protection  and  ready  adjust- 
ment of  the  instrument $5.00 

'3981  U.  S.  Weather  Bureau  Standard  Rain  and  Snow 
Gauge  of  galvanized  iron,  8 -inch  diameter,  25£ 
inches  high,  with  measuring-stick.  The  receiver 
has  a  capacity  for  2  inches  of  rainfall,  and  in 
connection  with  the  overflow  the  possible  capacity 
is  20  inches  of  rainfall.  The  Gauge  is  so  adjusted 
that  the  reading  is  magnified  10  times  and  1  inch 
of  rainfall  actually  measures  1 0  inches  on  the  stick .  .  6.00 
3982  Howard's  Rain  Gauge,  consisting  of  a  vertical  glass 
bottle,  through  the  neck  of  which  the  terminal 
tube  of  a  galvanized  iron  funnel,  5  inches  in 
diameter,  is  inserted.  A  glass  graduate,  measur- 
ing to  lOOths  of  an  inch,  is  furnished  with  the 
instrument.  .  4.00 


440 


&>  /I.  £.    GURLEY,    TROY,  M    K 
MINERS'  WATER   GAUGE 


3985 

No.  PRICE       POST. 

3985     Miners'  Water  Gauge,  for  ascertaining  the  ventilar 

ting  air-pressure  spent  on  airways  in  mines  ......      $3.75     $0.25 


MINERS'   LAMPS 


3987  3988  3989 

3987  Miners'  Lamp  (copper),  size  No.  2 $0.30     $0.10 

3988  Miners'  Safety  Lamp  (Newcastle  Davy  Lamp).  .  ..        2.50 

3989  Miners'  Safety  Lamp  (English  Clanny  Lamp,  bon- 

neted)         3.00 

HYDROMETERS 

WITH  BAUME'S  SCALE 

3990  Hydrometers,  for  testing  Acid,  Alkalies,  Ammonia, 

Bark,  Beer,  Ether  Milk,  Molasses,  Oils,  Salt 
Water,  Spirits,  Syrup,  Urine,  Vinegar.  Each...  $0.75  $0.10 
3995  Twaddel's  Hydrometers,  Nos.  1  to  6,  with  scales 
respectively  0  to  24,  24  to  48,  48  to  72,  72  to  100, 
100  to  134,  134  to  180,  each  graduation  repre- 
senting five  degrees  of  specific  gravity.  Each.  .  .  .75  .10 


SCIENTIFIC  BOOKS 

FOR    SALE    BY 

W.  &  L.  E.  GURLEY 

TROY,  N.  Y.,  U.  S.  A 


Architecture,      Carpentry     and     Building,      Astronomy,      Bridges, 
Roofs    and    Tunnels,    Chemistry    and    Physics,    Construction, 
Strength    of    Materials,  Drawing,  Electricity   and  Telegra- 
phy,  Geology,  Mining  and  Metallurgy,  Hydraulic  and 
Sanitary    Engineering,    Machinery    and    Mechan- 
ics,    Pocket     Table-Books,     Surveying     and 
Engineering  Instruments,  Etc. 


Parties  ordering  should  either  send  drafts  on  New  York, 
or  postal  orders  on  Troy,  N.  Y.;  or  if  money  is  enclosed  in 
letters,  such  letters  should  be  registered  at  the  post-office 
where  mailed. 

We  prepay  postage  on  nearly  all  American  and  English 
books  when  the  price  is  sent  to  us  in  advance. 

Books  can  be  registered  at  an  extra  cost  of  eight  cents 
for  each  package  of  not  over  four  pounds. 

Orders  for  over  $10  will  be  sent  by  express  C.  O.  D.  if 
desired ;  but  for  smaller  sums,  parties  will  please  remit  the 
necessary  amount  with  their  order. 

Write  all  letters  legibly,  give  your  Post-office,  County  and 
State,  and  be  sure  to  sign  your  letter  before  mailing. 

We  are  not  responsible  for  loss  of  goods  sent  by  mail. 

Should  any  other  works  on  kindred  topics  be  desired,  we 
will  furnish  them  at  publishers'  prices. 

441 


442  W.  &  L.  E.   GURLEY,   TROY,  N.    K 

ARCHITECTURE,   CARPENTRY,  AND  BUILDING 

PRICE 

BALDWIN,  W.  J.  Steam-Heating  for  Private  Houses  and  Large 

Buildings.  12mo.  404  pages.  131  illustrations $2.50 

BERG,  W.  G.  Buildings  and  Structures  of  American  Railroads. 

4to.  534  pages.  700  illustrations 5.00 

BUEL,  A.  W.,  and  HILL,  C.  S.  Reinforced  Concrete  in  Build- 
ing Construction.  8vo.  443  pages.  311  illustrations 5.00 

BULLOCK,  J.  Rudiments  of  Architecture  and  Building.  8vo. 

468  pages.  250  illustrations 2.50 

CARPENTER,  R.  C.  The  Heating  and  Ventilating  of  Buildings. 

8vo.  578  pages.  277  illustrations 4.00 

FREITAG,  J.  K.  Architectural  Engineering,  and  High  Building 

Construction.  8vo.  421  pages.  196  illustrations 3.50 

GRAVES,  H.  S.  Forest  Mensuration.  8vo.  472  pages.  Illus- 
trated.   4.00 

GREEN,  S.  B.  Principles  of  American  Forestry.  12mo.  347 

pages.  Illustrated 1.50 

HURST,  J.   T.      Hand- Book  for  Architectural  Surveyors 2.00 

KEMP,  EDWARD.  Landscape  Gardening.  403  pages.  204 

illustrations.  12mo 2.50 

KIDDER,  F.  E.  Building  Construction  and  Superintendence. 

Part  I.  Masons'  Work.  8vo.  421  pages.  260  illustrations.  4.00 

KIDDER,  F.  E.  Building  Construction  and  Superintendence. 
Part  II.  Carpenters'  Work.  8vo.  544  pages.  524  illustra- 
tions   4.00 

REID,  H.  A.  Concrete  and  Reinforced  Concrete  Construction. 

8vo.  800  pages.  700  illustrations 5.00 

TAYLOR,  F.  W.,  and  THOMPSON,  S.  E.  Treatise  on  Con- 
crete, plain  and  reinforced.  8vo.  585  pages.  Illustrated. .  .  5.00 

ASTRONOMY 

BOWDITCH,   N.      American  Practical  Navigator.     An  Epitome 

.  of  Navigation  and  Nautical  Astronomy.     8vo .     $2. 75 

CHAUVENET,  WM.      Spherical  and  Practical  Astronomy;  and 

the  Theory  and  Use  of  Fixed  Astronomical    Instruments.     2 

vols.,  royal  8vo ". 7.00 

COMSTOCK,   G.   C.      Field  Astronomy  for  Engineers.     8vo 2.50 

NAUTICAL  Almanac.      Published  by  authority  of  the  Secretary 

of  the  Navy,  Washington.      Each  year .75 

NAUTICAL  Almanac  and  Ephemeris.      Large  8vo.      Each  year  .        1.50 
NEWCOMB,   S.      Popular  Astronomy,  with   112  engravings  and 

5  maps  of  the  stars.     8vo 1 . 75 

PROCTOR,    R.    A.     Half-Hours   with   the   Telescope.       12mo. 

Illustrated 1.25 

PROCTOR,  R.  A.     Half-Hours  with  the  Stars.     A  plain  and  easy 

guide  to  the  knowledge  of  the  constellations,  with  explanation 

of  each  map.     True  for  every  year.     Demy  4to 2.00 


IV.  &  L.  E.   GURLEY,    TROY,  N.    Y.  443 

BRIDGES,  ROOFS,  ETC. 

PRICE 

BENDER,  C.  B.  Principles  of  Economy  in  the  Design  of  Metallic 

Bridges,  including  Cantilever  Bridges.  195  pages.  12  plates..  $2.50 

BOLLER,  A.  P.  Practical  Treatise  on  the  Construction  of  Iron 

Highway  Bridges.  Illustrated.  8vo 2.00 

BURR,  WM.  H.  Stresses  in  Bridges  and  Roof  Trusses,  Arched 
Ribs  and  Suspension  Bridges.  501  pages.  Illustrations  and 
13  plates.  8vo 3.50 

FOSTER,  W.  C.  Wooden  Trestle  Bridges.  The  present  practice 
on  American  railroads.  4to.  255  pages.  164  illustrations. 
47  plates 5.00 

GREENE,  C.  E.  Roof  Trusses.  Diagrams  for  Steady  Load, 

Snow  and  Wind.  8vo 1.25 

GREENE,  C.  E.  Bridge  Trusses.  Single,  Continuous,  and 
Draw-spans  ;  Single  and  Multiple  Systems ;  Straight  and  In- 
clined Chords.  8vo.  Illustrated.  10  plates 2.50 

GREENE,  C.  E.  Arches  in  Wood,  Iron,  and  Stone,  for  Roofs, 
Bridges,  and  Wall  openings  ;  Arched  Ribs  and  Braced  Arches, 
Stresses  from  Wind  and  change  of  Temperature.  8vo.  100 
pages.  60  illustrations.  8  plates 2.50 

HAUPT,  H.     Military  Bridges;  Trestle  and  Truss  Bridges.     8vo.        6.50 

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SCIENCE    SERIES 

iSMO.  FANCY  BOARDS,  jo   CENTS  EACH 


No. 

1  Chimneys  for  Furnaces,  Fire  Places,  and  Steam  Boilers.     By  R.  Arm- 
strong, C.  E. 

4  Proportion  of  Pins  Used  in  Bridges.     By  Chas.  E.  Bender,  C.  E. 

5  Ventilation  of  Buildings.     By  W.  F.  Butler. 

6  Designing  and  Construction  of  Reservoirs.     By  A.  Jacob,  A.  B. 

11  Theory  of  Arches.     By  Prof.  W.  Allan. 

12  Theory  of  Voussoir  Arches.      By  Prof.  W.  E.  Cain. 

13  Gases  met  with  in  Coal  Mines.      By  J.  J.  Atkinson. 

14  Friction  of  Air  in  Mines.     By  J.  J.  Atkinson. 

15  Skew  Arches.     By  Prof.  E.  W.  Hyde. 

17  Water  and  Water  Supply.     By  Prof.  W.  H.  Corfield. 

18  Sewerage  and  Sewage  Purification.     By  W.  N.  Baker,  Ph.  B. 

19  Strength  of  Beams  under  Transverse  Loads.    'By  Prof.  W.  Allan. 

20  Bridge  and  Tunnel  Centers.      By  E.  S.  Gould,  C.  E. 

22  High  Masonry  Dams.      By  John  B.  McMaster,  C.  E. 

23  Fatigue  of  Metals  under    repeated    Strains.      From   the   German   of 

Prof.  Spangenburgh,  with  a  Preface  by  S.  H.  Shreve,  A.  M. 

25  Theory  and  Calculation  of    Continuous  Bridges.      By  M.   Merriman, 

Ph.  D. 

26  Practical  Treatise  on  Continuous  Bridges.      By  Charles  Bender,  C.  E. 

31  Sanitary  Condition  of  Dwelling  Houses.      By  Geo.  E.  Waring,  Jr. 

32  Cable  Making  of  Suspension  Bridge.      By  Hildenbrand,  C.  E. 

33  Mechanics  of  Ventilation.      By  Geo.  W.  Rafter,  C.  E. 

34  Foundations.     By  Prof.  Jules  Gaudard,  C.  E. 

35  Aneroid  Barometer  :  Its  Construction  and  Use.   By  Geo.  W.  Plympton. 
38  Maximum  Stresses  in  Frame  Bridges.     By  Prof.  W.  E.  Cain,  A.  M. 

40  Transmission  of   Power  by  Compressed  Air.      By  R.  Zahner,  M.  E. 

41  Strength  of  Materials.     By  Wm.  Kent,  C.  E. 

42  Voussoir  Arches  Applied  to  Stone  Bridges,  Tunnels,  Culverts,  Groined 

Arches,  and  Domes.      By  Prof.  W.  E.  Cain,  C.  E. 

44  Turbine  Wheels.     By  Prof.  W.  P.  Trowbridge. 

48  Theory  of  Solid  and  Braced  Arches.      By  W.  E.  Cain,  C.  E. 

50  Dwelling  Houses  ;  their  Sanitary  Construction  and  Arrangements.     By 

Prof.  W.  H.  Corfield. 

55  Sewer  Gases  ;  their  Nature  and  Origin.     By  A.  de  Varona. 

56  Actual  Lateral  Pressure  of  Earthwork.     By  Benj.  Baker,  C.  E. 
68  Ventilation  of  Coal  Mines.     By  W.  Fairley. 

456 


SCIENCE   SERIES  457 

No. 

59  Railroad  Economics.     By  S.  W.  Robinson,  C.  E. 

60  Strength  of  Wrought   Iron  Bridge  Members.     By  S.  W.  Robinson, 

C.  E. 

61  Potable  Water:  and  Methods  of  Detecting   Impurities.     By  Chas. 

W.  Folkard. 

63     House  Drainage  and  Sanitary  Plumbing.     By  W.  P.  Gerhard,  C.  E. 
65     Pocket  Logarithms  to  Four  Places  of  Decimals. 
67     Hydraulic  Tables.     By  P.  J.  Flynn,  C.  E. 
72     Topographical  Surveying.     By  Geo.  J.   Specht,  Prof.  A.   S.  Hardy, 

John  B.  McMaster  and  H.  F.  Walling. 
74     Testing  Machines,  their  History,  Construction  and  Use.     By  Arthur 

V.  Abbott. 
77     Stadia  Surveying  and  Stadia  Measurements.      By  A.  Winslow. 

80  Healthy  Foundations  for  Houses.     By  Glenn  Brown. 

81  Water  Meters  :  Comparative  Tests  of  Accuracy,   Delivery,  etc.      By 

Ross  E.  Browne. 

82  Preservation  of  Timber  by  the  Use  of    Antiseptics.      By  S.  B.  Boul- 

ton,  C.  E. 

83  Mechanical  Integrators.      By  Prof.  Henry  S.  H.  Shaw,  C.  E. 

84  Flow  of  Water  in  Open  Channels,    Pipes,    Conduits,   Sewers,  etc.; 

with  Tables.      By  P.  J.  Flynn,  C.  E. 

87  Treatise  on  the  Theory  of  the  Construction  of  Helicoidal   Oblique 

Arches.     By  John  L.  Culley,  C.  E. 

88  Beams  and  Girders.      Formulas  for  their  Resistance.      By  Prof.  P.  H. 

Philbrick. 

91     Leveling  ;  Barometric,  Trigonometric,  and  Spirit.     By  Prof.   I.   O. 
Baker. 

93  Notes    Embodying    Recent    Practice   in   the    Sanitary    Drainage   of 

Buildings.      By  Wm.  Paul  Gerhard,  C.  E. 

94  Treatment  of  Sewage.     By  Dr.  C.  Meymott  Tidy. 

95  Plate  Girder  Construction.      By  Isami  Hiroi,  C.  E. 

100  How  to  Become  an  Engineer.      By  G.  W.  Plympton,  C.  E. 

101  The   Sextant  and  other  Reflecting  Mathematical   Instruments.      By 

F.  R.  Brainard,  U.  S.  Navy. 
104     Van  Nostrand's  Table  Book  for  Civil    and    Mechanical    Engineers. 

Compiled  by  Prof.  Geo.  W.   Plympton. 

107     Graphical  Method  for  Swing- Bridges.      By  B.  F.  LaRue,  C.   E. 
110     Transition  Curves.     By  W.  G.  Fox. 

114  Manual  of  the  Slide-Rule.     By  F.  A.  Halsey. 

115  Traverse  Table,   for  distances  between   1   and  100,    and  for  every 

quarter  degree  up  to  90  degrees. 

Any  of  the  Science  Series  not  mentioned    in    the    above   list  will  be 
furnished  promptly  on  application. 


DEPARTMENT    P 

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TROY,  N.  Y.,  U.  S.  A. 

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POLYTECHNIC   INSTITUTE 

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It  is  the  aim  of  the  Institute  to  maintain  the  most  thor- 
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instruction  are  the  result  of  an  experience  unequaled  by  that 
of  any  similar  school  in  the  world.  The  Course  of  Study 
pursued,  while  not  beyond  the  capacity  of  young  men  of 
average  ability,  is  constantly  adjusted  to  the  progress  of  the 
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It  should  be  stated,  perhaps,  that  Civil  Engineering  is 
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The  studies  of  the  course  are  designed  as  a  professional 
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ing specialties  of  engineering  practice  : 

461 


462         RENSSELAER   POLYTECHNIC  INSTITUTE 

The  location,  construction,  and  superintendence  of  public 
works,  as  steam  and  electric  railways,  canals,  water  works, 
etc.;  the  design,  construction  and  management  of  mills,  iron 
works,  steel  works,  chemical  works,  and  pneumatic  works; 
the  design  and  construction  of  roofs,  arch  bridges,  girder 
bridges,  and  suspension  bridges;  the  survey  and  superintend- 
ence of  hydraulic  motors,  air  engines,  electric  motors,  and 
the  various  kinds  of  steam  engines;  the  design,  construction 
and  use  of  machines  in  general,  and  the  determination  of 
their  efficiency ;  the  survey  of  rivers,  lakes,  and  harbors,  and 
the  direction  of  their  improvements ;  the  determination  of 
latitude,  longitude,  time,  and  the  meridian  in  geographical 
explorations,  or  for  other  purposes,  together  with  the  projec- 
tion of  maps;  the  selection  and  test  of  materials  used  in  con- 
struction ;  the  construction  of  the  various  kinds  of  geometrical 
and  topographical  drawings.  • 

A  course  of  study  is  also  pursued  in  the  Institute  embracing 
more  advanced  instruction  in  Natural  History,  Chemistry,  and 
Geology,  leading  to  the  degree  of  Bachelor  of  Science.  The 
first  two  years  are  identical  with  the  course  in  Civil  Engineering. 

Special  students  in  all  courses,  particularly  in  chemistry 
and  electrical  engineering,  are  also  received. 

There  are  two  terms  in  the  scholastic  year  and  the  tuition 
is  $100  per  term.  Other  expenses  are  largely  within  the  con- 
trol of  individual  students.  Every  effort  is  made  by  the  man- 
agement to  keep  necessary  expenses  within  the  narrowest 
limits,  consistent  with  the  best  opportunities  to  students,  and 
they  have  been  materially  reduced  within  the  last  few  years. 

Any  one  desiring  a  thorough  course  of  study  in  prepara- 
tion for  advanced  professional  work  in  any  department  of 
engineering  is  invited  to  apply  for  further  information  to  the 
President  of  the  Institute. 


RENSSELAER    POLYTECHNIC   INSTITUTE        463 

'The  greatest  number  of  the  renowned  hydraulic  and  railroad  engi- 
neers of  America  are  graduates  of  this  school." — From  the  report  to  his 
government  of  Professor  A.  Riedler  of  the  Royal 
(Report  U.  S.  Commissioner  of  Education,  1892-' 


"This  famous  Institute  is  by  no  means  local,  as  the  freshman  list  this  year 
contains  the  names  of  students  from  twenty-two  States  of  the  Union,  as  well 
as  from  Cuba  and  South  America,  and  the  graduates  are  leading  men  in 
engineering  and  in  business  all  over  the  world." —  The  Railroad  Gazette, 
February  22,  1901, 


ROADS, 

RAILROADS, 

BRIDGES, 

ARCHES, 

DAMS. 
STEAM    ENGINES, 

ELECTRIC    ENGINES, 

DYNAMOS, 

TURBINES. 
FOUNDATIONS, 

WATER    WORKS, 

TUNNELS, 

SEWERS, 

RIVERS, 

CANALS. 
CHEMICAL  ANALYSIS, 

.    MINERALOGY, 

METALLURGY, 

ASSAYING. 


TABLE   OF  CONTENTS 


PAGE 

Abney  Level  and  Clinometer 244,  291 

Acoustic  Current  Meter '. 231,  291 

Adjustment  of  Architects'  Level 179 

Adjustment  of  Drainage  Level 183 

Adjustment  of  Engineers'  and  Surveyors'   Transits 21-26 

Adjustment  of  Engineers'   Y  Level 169-174 

Adjustment  of  Line  of  Collimation. 22,  138,  171 

Adjustment  of  Objective  Slide .  . 25,  169 

Adjustment  of  Solar  Attachment 93-95 

Adjustment  of  Solar  Compasses 108,  144 

Adjustment  of  Surveyors'  Compasses .  124 

Adjustment  of  Telescopic   Sight 137 

Air   Meters 424-426 

Alidades  for  Plane-Tables 212-214,  216,  289 

Alt- Azimuth 413 

Alteneder  Drawing- Instruments 318—322 

Aluminum  Instruments • .  . 160,  257,  279 

Anemometers 424—426 

Aneroid  Barometers 420-423 

Angle  Mirrors 416 

Architects'    Levels .177-181,  280 

Artificial  Horizon . .  .- 416 

Astronomical  Telescopes 431 

Astronomical    Terms 97-102 

Attachments  and  Extras  for  Compasses .133,  137,  152,  276,  277 

Attachments  and  Extras  for  Transits 54—77,  274,  275 

Ball-Spindle 120,  131,  264,  276 

Barometers,   Aneroid 420-423 

Batson    Sketching-Case 217,  290 

Battery  for  Current  Meters 228,  290 

Beaman  Stadia  Arc 62,  274 

Binocular  Hand  Level 241,  242,  291 

Blowpipes 437 

Blue-print  Paper,  Print  Frames  and  Bath  Trays 383-385 

Books,  Blank,  for  Field  Notes 392-394 

Books,  Scientific,  for  Architects,    Draftsmen,    Engineers  and  Sur- 
veyors    441-457 

Boxes  and  Cases  for  Compasses,  Levels  and  Transits 264,  265,  282 

Boxes  and  Cases  for  Drawing- Instruments 310,  323 

Boxwood  Rules  and  Scales 352-359 

Boyden  Hook-Gauge 239,  290 

Bristol  Board 380 

464 


TABLE    OF  CONTENTS  465 

PAGE 

Bronze  Finish 257 

Brushes  for  Water-Colors 406,  407 

Builders'  Transit 50,  274 

Celluloid  or  Amber  Goods 347,  348,  363,  364,  366,  370,  372,  376 

Center- Pin 128 

Chains,  American. . '. 245-247,  292 

Chains,  Metric  and  Vara 248,  293 

Chain  Tapes .    .  .249,  294 

Clamp  and  Tangent 13,  59,  61,  137,  274,  277,  278 

Clinometers 155,  243,  279,  412,  413,  419 

Colors,  Winsor  &  Newton's 401,  403-405 

Compass  Attachments  for  Levels 165,  183,  280 

Compasses,  Clinometer 155,  279 

Compasses,  Dial 158-160,  279 

Compasses,  Extras  for 133,  137,  152,  276,  277 

Compasses,  Geologists' 153,  279 

Compasses,  Miners'  Dip-Needle 156,  279 

Compasses,  Plain 130,  152,  276,  278 

Compasses,  Pocket 142-160,  277-279,  410-414 

Compasses,  Prismatic  413,  414 

Compasses,  Railroad 1 112,  145,  276-278 

Compasses,  Solar 106,  142,  275,  277 

Compasses,  Vernier 117,  149,  276,  278 

Compound  Tangent  Ball-Spindle 131,  276 

Crayon  Pencils  and  Lumber  Crayons 395,  396 

Cross- Section  Books  and  Paper 386,  389,  390,  394 

Cross-Staff  Heads 416 

Cross-Wires 8,  24,  262,  263,  264,  265 

Current  Meter  Reduction  Tables. 229,  232,  236 

Current  Meters 223-238,  290 

Curves  of  Amber,  Rubber  and  Wood 376,  377 

Declination  Arc 70,  94,  143 

Declination  of  Magnetic  Needle 121-123 

Declination  of  the  Sun 73,  83,  84,  98 

Detachable  Telescopes  for  Transits 66,  276 

Diagonal  Prism  for  Eyepiece  of  Telescopes 67,  275 

Dial  Compasses 158-160,  279 

Dip-Needle  Compasses 156,  279 

Diurnal  Variation 123 

Drainage  Levels 182,  280 

Drawing- Boards  and  Tables 367,  368 

Drawing- Instruments,  Alteneder 318—322 

Drawing- Instruments,  Brass 338-342 

Drawing- Instruments,  German 324-342 


TABLE    OF  CONTENTS 

PAGE 

Drawing-Instruments,  Nickel-plated 310-342 

Drawing- Instruments,  Pivot -joint 31o-323 

Drawing- Instruments,  Swiss 302-8x7,  343-345 

Drawing-Paper 380-383,  387-390 

Dust  Guard  for  Objective  Slide  of  Telescope 11,  162,  267,  275 

Electric  Current  Meter ' 233-238,  290 

Electricity 126 

Electric  Register 224,  228,  290 

Ellipses 376 

Empty  Cases  for  Instruments 264,  265,  282,  310,  323 

Engineers'  Levels 162,  280 

Engineers'  Transits 6,  28-31,  270,  271 

Erasing- Knives  and  Erasing- Rubber 397-399 

Excavation  and  Embankment  Tables 394,  451,  452 

Explorers'   Transit 32-34,  27 1 

Extras  for  Compasses 133,  137,  152,  276,  277 

Extras  for  Transits 54-77,  274,  275 

Eyepiece  for  Transit  and  Level  Telescope 5,  7,  264,  265 

Eyepiece  of  Telescope,  how  composed 5-7 

Field-Glasses  and  Telescopes  for  Tourists 427—430 

Flagstaff  or  Ranging-Pole 203,  285,  286 

Foreign  Shipment 258,  259 

Geologists'  Compass 153,  279 

Gradienter 64,  274 

Graduations  of  Limb  and  Vertical  Circle 14-18,  19,  262,  266,  275 

Hand  Levels. .  .  241-244,  291 

Hook-Gauge,  Boyden's 239,  240 

Hour  Circle  and  Hour  Arc 70,  95,  144,  159,  279 

Hydrometers 

Hygrometer 

Hyperbolas 376 

India  Ink 401,  402 

Information  to  Purchasers 

Ink  for  Drawing  or  Writing 383,  401,  402 

Ink-Slabs  and  Color-Saucers 407>  408 

Inverting  Eyepiece  .  .  

Ivory  Rules  and  Scales 351-353,  359 

Lacquering 

Latitude  Arc 70,  91,  92,  143,  275 

Latitude  Level 90,  275 

Leather  Cases  and  Pouches.  .  190>  282 


TABLE    OF  CONTENTS    ,  467 

PAGE 

Leveling- Adopter 131,  152,  276,  278 

Leveling- Instruments,  Architects' 177-181,  280 

Leveling-Instruments,  Drainage 182-184,  280 

Leveling- Instruments,  Y  Levels 162,  177,  280 

Leveling- Rods 191-203,  283-286 

Leveling  Tripod  Head 19,  132,  169,  267,  275,  276,  278 

Level  on  Telescope 59,  137,  274,  277 

Level-Vials  and  Spirit-Levels  . .  .13,  22,  117,  124,  128,  167,  172,  435,436 

Limbs  of  Transits 14-18,  266 

Line  of  Collimation 22-24,  138,  171 

Locke  Level 243,  291 

Magnetic  Needle 12,  74,  110,  115,  121,  124,  127 

Magnets 437 

Magnifiers 61,  275,  432-434 

Magnifying  Power  of  Telescope 7,  8 

Marking- Pins  and  Timber-Scribe 249,  293 

Meters,  Current 223-238,  290 

Metric  Aneroid  Barometers 421 

Metric  Chains  and  Tapes 248,  2ol,  292,  298 

Metric  Leveling- Rods  and  Poles 201,  208,  284,  285,  286 

Metric  Paper  for  Draftsmen 388,  390 

Metric  Rules  and  Scales 357,  362 

Miners'  Dip-Needle  Compasses 156,  279 

Miners'  Lamps  and  Water  Gauge 440 

Miscellaneous 265,  455 

Monocular  Hand  Level 241,  242,  291 

Mountain  Transits 35,  271 

Mucilage 400 

Objective  of  Telescopes  5,  264,  265 

Odometers 418 

Offset  Standard 134,  277 

Oilstones 436 

Opera  and  Field-Glasses  427,  428 

Optical  Axis 8,  134 

Optical  Principle  of  Telescope 5>  ? 

Outkeeper 

Packing  and  Shipping ' 258,  260,  267 

Pantographs 3^9 

Paper  Cutter.  .  

Paper,  Drawing  and  Tracing 380-383,  386-390 

Parabolas  .  .  

Parallel  Rulers. 378,  379 

Parchment  Paper 382>  383 


468  TABLE    OF  CONTENTS 

PAGB 

Parts  of  Instruments  liable  to  injury,  Prices  of 264,  265 

Passometers 417 

Payment,  Terms  of 255,  263 

Ped<5meters 417 

Pencils 395 

Pencil- Sharpeners   „ . .  397 

Pens,  Mapping  and  Writing 396 

Plain  Compasses 130,  152,  276,  278 

Plane-Tables 205,  287-289 

Planimeters 310,  311 

Platinum  Cross- Wires 8,  24,  262,  263,  264,  265 

Plummet  Lamp 68,  275 

Plummets 265,  281 

Pocket  Compasses 142-160,  277-279,  410-414 

Pocket  Levels 435 

Polar  Axis 94 

Price  List 264-457 

Prismatic  Compasses 413,  414 

Profile-Books  and  Paper 387,  388,  392 

Protractors  of  Boxwood,    Brass,   Celluloid,  German  Silver,  Horn, 

Ivory,  Paper,  Rubber  and  Wood 343-352 

Protractors,  Limb,  long  steel  blade 345,  346 

Quick-Leveling  Attachment 275 

Rack  and  Pinion 5,  166,  266S  275,  278 

Railroad  Compasses . 112,  145^148,  276-278 

Rain  Gauge  and  Water  Gauge ." •  439 

Ranging-Poles 203,  286 

Reading-Glasses  and  Magnifiers 432-484 

Reconnoissance  Transit 48,  273 

Reflecting  Mirrors  and  Prisms 416 

Reflectors  for  Cross- Wires  and  Limb  of  Transits 19,  67,  267,  275 

Refraction 77,  102 

Refractions,   Table   of 78-82 

Rensselaer  Polytechnic   Institute 459 

Repairs  to  Instruments 260-263 

Rod  Level 204,  286 

Rods,    Leveling 191-202,  283-286 

Rubber  Goods 363-365,  370,  372,  375-378,  397-399 

Scales  of  Boxwood,  Ivory,  Paper  and  Metal 351-361 

r-        •         T  •  QKO     374. 

Section- Liners 6 ' °>  6 /4 

Selection  of  Instruments 253 

Sextants 

Shifting  Center  for  Leveling-Head  of  Transits 20,  266 


TABLE    OF  CONTENTS  469 

PAGE 

Short  Focus 11,  162,  266 

Sights  on  Standards  and  on  Telescope  of  Transists 61,  275 

Sizes  of  Compasses 113,  116,  120,  130,  149,  152 

Sizes  of  Levels 177 

Sizes  of  Transits 28,  32,  42,  45,  48,  53 

Sketch  Blocks,  Paper 386 

Sketching-Case,  Batson ; 217,  290 

Slide-Rules 358,  361 

Slope-Levels 419 

Sockets  of  Levels . .  . . 164,  168 

Sockets  of  Transits 18,  19,  28,  35,  41,  43,  45 

Solar  Attachment  for  Transits 30,  37,  46,  69-77,  275 

Solar  Compasses 106,  142,  275,  277 

Solar  Screen 89,  275 

Solar  Transits 30,  37,  46,  271-273 

Special  Notice 266 

Spirit-Levels    13,  22,  118,  124,  128,  167,  264,  265,  435 

Spring-Balance  for  Chains  and  Tapes 291 

Stadia  Arc 62,  274 

Stadia  Rods 199,  283 

Stadia  Wires 9-11,  262,  263,  267,  275 

Staff  Mountings 120,  264 

Steel  Rules 362 

Steel  Tapes 249-251,  294-299 

Stencil  Alphabets  and  Figures 408,  409 

Straight-Edges  of  Amber,  Rubber,  Wood  and  Steel 362-364 

Striding- Level 95,  275 

Surveyors'  Cross-Staff  Head 416 

Surveyors'  Transits , 39-47,  272,  273 

Tables,  Drawing 367,  368 

Tables,  Plane 205,  287-289 

Tables,  Reduction,  for  Current  Meters 229,  232,  236 

Tables,  Traverse  (books)  .... 451,  457 

Tacks  for  Drawing- Boards 391 

Tally  Register _       418 

Tangent  Scale  on  Sight  Vanes 119 

Tape  Lines,  Metallic 250,  295 

Tape  Lines,  Steel 249-251,  294-299 

Telescope,  how  composed 5-7,  162 

Telescopes  and  Tourists'  Glasses 427-431 

Telescopes  for  Vertical  Sighting 66,  275 

Telescopic  Sight  Attachment 133-139,  277 

Thermometers 437,  488 

Timber-Scribe  or  Marking-Iron 293 

Time-Recorder  for  Current  Meters 227,  291 

Tin  Tubes  for  Drawing  Paper 386 


470  TABLE    OF  CONTENTS 

PAGE 

Tracing-Cloth  and  Paper 383 

Trammel  Points 436,  437 

Transit- instruments,  General  Description 5-26 

Transits,  Attachments  for. .' 54-77,  274,  275 

Transits,  Builders' ' 50,  274 

Transits,  Engineers' 6,  28,  270,  271 

Transits,  Explorers' 32,  271 

Transits,  Light  Mountain  and  Mining 35,  271 

Transits,   Reconnoissance 48,  273 

Transits,   Solar 30,  37,  46,  271-273 

Transits,  Solar  Attachment  for 69-76,  275 

Transits,   Surveyors' 39-47,  272,  273 

Transits,  Vernier 52,  274 

Transportation 259 

Traverse  Table  Board  and  Tripod 215,  289 

Traverse  Tables  (books) 451,  457 

Trial  of  Instruments 256 

Triangles  of  Amber,  German  Silver,  Rubber,  Steel  and  Wood. . .  369-372 

Tripods : 20,.  186-189,  207,  280,  281 

T-Squares  of  Amber,  Rubber,  Steel  and  Wood 364-366 

Vara  Chains  and  Tape  Lines 248,  251,  293,  298 

Variation  Arc  of  Transits 13,  267,  274 

Variation  of  the  Magnet  Needle 115,  121-123 

Vellum  or  Tracing-Cloth 383 

Vernier  Compasses 117-129,  149,  276,  278 

Vernier  Protractors 344-347 

Verniers 18,  117,  121 

Vernier  Transit  Compasses 52,  274 

Vertical  Arc  and  Vertical  Circle 55-58,  137,  266,  274,  277 

Warranty 255 

Water-Colors 401,  403-405 

Water-Glasses 407 

Weights  of  Compasses 106,  113,  116,  121,  130,  144,  148,  150 

Weights  of  Levels 177 

Weights  of  Transits 28,  34,  38,  42,  45,  48,  51,  53 

Ys  of  Leveling- Instruments 168,  173 


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